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• Parents' migration status is associated with infant's timely vaccination. • Having a foreign-born mother is positively associated with infant's timely vaccination. • Having a foreign-born father is positively associated with infant's timely vaccination. • Among migrant population, odds of timely vaccination decreases as length of stay increases. • Future research may explore factors behind lower rates of timely vaccination among settled migrants. Migration has been recognized as an important determinant of child health outcomes including childhood vaccination status. This paper aims to examine the association between parental migration status and a less studied aspect of child immunization outcomes, namely timeliness, within the context of New Zealand (NZ), a country characterized by a substantial proportion of its resident population born overseas. Additionally, the study explored the impact of residential duration on children's immunization timeliness. The data was taken from a large, representative population-based cohort study in NZ (Growing Up in NZ study). A total of 6156 children and their parents, comprising 2241 foreign-born and 3915 NZ-born mothers and a sub-group of their partners were included in the analysis. The survey data was linked with the National Immunization Register dataset. Timely immunization was defined as receiving two vaccines at each scheduled vaccination point (at six-week, three-month, and five-month, totaling six doses of vaccines) within 30 days of their due date. We examined the associations between parental migration status, maternal residential duration, and child immunization timeliness while controlling for socio-economic variations. The results were presented as adjusted odds ratios (AORs) with 95 % confidence intervals (CIs). The findings revealed that after adjustment for socioeconomic differences, children of foreign-born mothers exhibited higher odds of receiving all six studied vaccine doses on time compared to children of native-born mothers (AOR 1.51, 95 %CI:1.27–1.78). Similarly, having a foreign-born father was also significantly associated with timely completion of all six vaccine doses. Children of recent immigrants who had resided in the country for less than five years demonstrated higher odds of timely vaccination of all six vaccine doses compared to children of settled immigrants who had lived in the country for five or more years (AOR 1.65, 95 %CI: 1.25–2.19). This study revealed a significant pattern in NZ where immigrants exhibited higher rates of timely immunization for their children compared to native-born parents. However, the findings also underscore the importance of providing support to settled immigrants, as their children experienced declines in timely vaccination rates compared to children of recent immigrants and even those born to NZ-born parents. [ABSTRACT FROM AUTHOR]

In January 2018, Afghanistan introduced the monovalent oral rotavirus vaccine (Rotarix) nationwide, administered as a 2-dose series at six and ten weeks of age. We describe characteristics of intussusception cases and assess potential intussusception risk associated with Rotarix vaccination in Afghan infants. Multi-center prospective active hospital-based surveillance for intussusception was conducted from May 2018 to March 2022 in four sentinel sites in Afghanistan. We applied the Brighton Level 1 criteria for intussusception and verified vaccination status by reviewing vaccine cards. We used the self-controlled case series (SCCS) methodology to compare intussusception incidence in the 1 to 21 days after each dose of Rotarix vaccination against non-risk periods. A total of 468 intussusception cases were identified in infants under 12 months, with 264 cases aged between 28 and 245 days having confirmed vaccination status contributing to the SCCS analysis. Most case-patients (98 %) required surgery for treatment, and over half (59 %) of those who underwent surgery required intestinal resection. Nineteen (7 %) case-patients died. Eighty-six percent of case-patients received the first dose of Rotarix, and 69 % received the second dose before intussusception symptom onset. There was no increased risk of intussusception in the 1–7 days (relative incidence: 0.9, 95 % CI: 0.1, 7.5), 8–21 days (1.3, 95 % CI: 0.4, 4.2), or 1–21 days (1.1, 95 % CI: 0.4, 3.4) following receipt of the first dose or in the 1–7 days (0.2, 95 % CI: 0.3, 1.8), 8–21 days (0.7, 95 % CI: 0.3, 1.5), or 1–21 days (0.6, 95 % CI: 0.3, 1.2) following the second dose. Rotarix vaccination was not associated with an increased intussusception risk, supporting its continued use in Afghanistan's immunization program. However, there was a high level of death and resection due to intussusception among Afghan infants. [ABSTRACT FROM AUTHOR]

• Flu vaccine uptake in pregnant women was in 6.2–37.5 % in the flu seasons 2010–2020. • Flu vaccinations are protective for pregnant women in the season of vaccination. • Maternal flu vaccinations protect infants in the season of vaccination. Influenza vaccinations are recommended in pregnancy to protect both the pregnant woman and the unborn baby. The aim of this study was to assess the influenza vaccine uptake among pregnant women in Iceland in ten influenza seasons and to estimate the influenza disease burden on pregnant women and their infants. This was a retrospective, descriptive study on influenza vaccine uptake among pregnant women and the burden of influenza and influenza-like illness (ILI) among pregnant women and their infants in ten influenza seasons. All women attending a 20-week ultrasound at Landspitali University Hospital in Reykjavik in August-April each influenza season 2010–2020 were included in the study. Data on influenza vaccinations and influenza/ILI diagnoses was collected from central national databases. The influenza vaccine uptake increased from 6.2 % in 2011–2012 to 37.5 % in 2019–2020. The incidence rate of influenza/ILI among pregnant women ranged from 5.5 to 22.1/1000 person-years. The estimated vaccine effectiveness in the ten influenza seasons was 34–100 %. The incidence rate of influenza/ILI among infants < 12 months of age was 0–13.4/1000 person-years. Influenza vaccinations in pregnancy are protective against influenza/ILI in pregnant women (IRR 0.36, 95 % CI 0.22–0.58), infants in the season of vaccination (IRR 0.40, 95 % CI 0.17–0.97) and probably for infants < 6 months of age (IRR 0.51, 95 % CI 0.22–1.21). Influenza vaccine coverage in pregnancy is suboptimal. Influenza vaccinations in pregnancy provide significant protection against influenza/ILI for pregnant women and infants in the season of vaccination. Initiatives to improve maternal vaccination coverage are needed. [ABSTRACT FROM AUTHOR]

BACKGROUND: Streptococcus pneumoniae is a leading cause of severe infections among children. Despite vaccination, HIV-exposed, uninfected (HEU) children have a higher incidence of invasive pneumococcal disease than HIV-unexposed, uninfected (HUU) children. We sought to compare the immunogenicity of 13-valent pneumococcal conjugate vaccine (PCV-13) in HEU and HUU infants. METHODS: We conducted a prospective cohort study of 134 mother-infant dyads in Botswana. Infants received PCV-13 doses at 2, 3, and 4 months through routine clinical care. We measured IgG antibodies specific to vaccine serotypes in sera collected from infants at 0, 5, and 12 months of age. We calculated the proportion of infants with protective IgG levels (≥0.35 µg/mL) to specific pneumococcal serotypes. RESULTS: At birth, fewer than half of infants had protective IgG levels to serotypes 1 (38%), 3 (46%), 4 (33%), 5 (23%), 6B (40%), 7F (44%), 9 V (44%), and 23F (46%). Compared to HUU infants (n = 97), HEU infants (n = 37) had lower antibody concentrations at birth to serotypes 5 (p = 0.046) and 19A (p = 0.008) after adjustment for maternal age and infant birth weight. More than 80% of HEU and HUU infants developed protective antibody levels to each of the 13 vaccine serotypes following PCV-13 vaccination. Median concentrations of antibodies to pneumococcal serotypes declined by 55-93% between 5 and 12 months of age, with fewer than half of infants having protective antibody levels to serotypes 1 (47%), 3 (28%), 9 V (44%), 18C (24%), and 23F (49%) at 12 months of age. CONCLUSIONS: Both HEU and HUU infants developed protective antibody responses to PCV-13 administered in a 3 + 0 schedule. However, antibody concentrations to many pneumococcal serotypes waned substantially by 12 months of age, suggesting that a PCV-13 booster dose in the second year of life may be needed to maintain protective pneumococcal antibody levels in older infants and young children.

As of June 2023, two pneumococcal conjugate vaccines, 20- (PCV20) and 15- (PCV15) valent formulations, are recommended for US infants under a 3 + 1 schedule. This study evaluated the health and economic impact of vaccinating US infants with a new expanded valency PCV20 formulation. A population-based, multi cohort, decision-analytic Markov model was developed to estimate the public health impact and cost-effectiveness of PCV20 from both societal and healthcare system perspectives over 10 years. Epidemiological data were based on published studies and unpublished Active Bacterial Core Surveillance System (ABCs) data. Vaccine effectiveness was based on PCV13 effectiveness and PCV7 efficacy studies. Indirect impact was based on observational studies. Costs and disutilities were based on published data. PCV20 was compared to both PCV13 and PCV15 in separate scenarios. Replacing PCV13 with PCV20 in infants has the potential to avert over 55,000 invasive pneumococcal disease (IPD) cases, 2.5 million pneumonia cases, 5.4 million otitis media (OM) cases, and 19,000 deaths across all ages over a 10-year time horizon, corresponding to net gains of 515,000 life years and 271,000 QALYs. Acquisition costs of PCV20 were offset by monetary savings from averted cases resulting in net savings of $20.6 billion. The same trend was observed when comparing PCV20 versus PCV15, with a net gain of 146,000 QALYs and $9.9 billion in net savings. A large proportion of the avoided costs and cases were attributable to indirect effects in unvaccinated adults and elderly. From a health-care perspective, PCV20 was also the dominant strategy compared to both PCV13 and PCV15. Infant vaccination with PCV20 is estimated to further reduce pneumococcal disease and associated healthcare system and societal costs compared to both PCV13 and PCV15. [ABSTRACT FROM AUTHOR]

To describe self-reported reactogenicity, pregnancy outcomes, and SARS-CoV-2 infection following COVID-19 vaccination during pregnancy. National, prospective cohort study. Participants across Canada were enrolled from July 2021 until June 2022. Individuals pregnant during the COVID-19 pandemic, regardless of vaccination status, were included. The Canadian COVID-19 Vaccine Registry for Pregnant and Lactating Individuals (COVERED) was advertised through traditional and social media. Surveys were administered at baseline, following each vaccine dose if vaccinated, pregnancy conclusion, and every two months for 14 months. Changes to pregnancy or vaccination status, SARS-CoV-2 infections, or significant health events were recorded. Reactogenicity (local and systemic adverse events, and serious adverse events) within 1 week post-vaccination, pregnancy and neonatal outcomes, and subsequent SARS-CoV-2 infection. Among 2868 participants who received 1–2 doses of a COVID-19 vaccine during pregnancy, adverse events described included: headache (19.5–33.9%), nausea (4.8–13.8%), fever (2.7–10.2%), and myalgia (33.4–42.2%). Reactogenicity was highest after the 2nd dose of vaccine in pregnancy. Compared to 1660 unvaccinated participants, there were no statistically significant differences in adverse pregnancy or infant outcomes, aside from an increased risk of NICU admission ≥ 24 h among the unvaccinated group. During follow-up, there was a higher rate of participant-reported SARS-CoV-2 infection in the unvaccinated compared to the vaccinated group (18[47.4%] vs. 786[27.3%]). Participant-reported reactogenicity was similar to reports from non-pregnant adults. There was no increase in adverse pregnancy and birth outcomes among vaccinated vs. unvaccinated participants and lower rates of SARS-CoV-2 infection were reported in vaccinated participants. Tweetable abstract: No significant increase in adverse pregnancy or infant outcomes among vaccinated versus unvaccinated pregnant women in Canada. [ABSTRACT FROM AUTHOR]

The European Society of Pediatric Infectious Diseases (ESPID) hosted the third Group B Streptococcus (GBS) Research Session in Athens on 11th May 2022, providing researchers and clinicians from around the world an opportunity to share and discuss recent advances in GBS pathophysiology, molecular and genetic epidemiology and how these new insights can help in improving prevention and control of early- and late-onset GBS disease. The meeting provided a state-of-the-art overview of the existing GBS prevention strategies and their limitations, and an opportunity to share the latest research findings. The first presentation provided an overview of current GBS prevention and treatment strategies. In the second presentation, the genomic and antimicrobial resistance profiles of invasive and colonizing GBS strains were presented. The third presentation explained the association of intrapartum antibiotic prophylaxis (IAP) with the development of late-onset disease (LOD) and the interplay of host innate immunity and GBS. The fourth presentation evaluated the role of genomics in understanding horizontal GBS transmission. The fifth presentation focused on the zoonotic links for certain GBS lineages and the last presentation described the protective role of breastmilk. Talks were followed with interactive discussions and concluded with recommendations on what is needed to further GBS clinical research; these included: (i) the development of better risk stratification methods by combining GBS virulence factors, serological biomarkers and clinical risk factors; (ii) further studies on the interplay of perinatal antimicrobials, disturbances in the development of host immunity and late-onset GBS disease; (iii) routine submission of GBS isolates to reference laboratories to help in detecting potential clusters by using genomic sequencing; (iv) collaboration in animal and human GBS studies to detect and prevent the emergence of new pathogenic sequence types; and (v) harnessing the plethora of immune factors in the breastmilk to develop adjunct therapies. [ABSTRACT FROM AUTHOR]

Immunisation during pregnancy with a tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine can protect infants against pertussis between birth and paediatric vaccination. We aimed to estimate the vaccine effectiveness (VE) of third-trimester pregnancy immunisation with the three-component acellular pertussis (Td3ap) vaccine at preventing pertussis in infants <2 months in the United States (US), to support a label update. We performed a post-hoc sub-analysis of a case-control study conducted in six US Emerging Infections Program Network states between 2011 and 2014. Our analysis included only cases and controls whose mothers were either vaccinated with Td3ap or did not receive any Tdap vaccine. The association between Td3ap maternal immunisation and pertussis in infants was assessed for US data using a frequentist method with conditional logistic regression. A robustified analysis was conducted using Bayesian dynamic borrowing of non-US data, considering a mixing-weighted prior of 90% for historical non-US VE data, and of 10% for a vague prior. VE was estimated as (1- odds ratio) × 100%. Sensitivity analyses accounting for the impact of each non-US study, different mixing weights and missing/ambiguous data were performed. We included 108 cases and 183 controls. Based on US data, the estimated VE of third-trimester maternal immunisation with Td3ap at preventing pertussis in infants <2 months was 78.0% (95% confidence interval: −38.0; 96.5). VE estimated by Bayesian dynamic borrowing of non-US data (with a 90% weight for historical data) was 83.4% (95% credible interval: 55.7; 92.5); sensitivity analyses produced similar VE estimates. Effectiveness of third-trimester pregnancy immunisation with Td3ap at preventing infant pertussis in the US is very likely to be ≥ 50% and is most likely ∼ 80%. Bayesian dynamic borrowing of non-US VE data allowed overcoming the limited power (due to small sample size) of a brand-specific sub-analysis by considering additional evidence. [ABSTRACT FROM AUTHOR]

• Time from US infant birth hospitalization discharge to the first outpatient visit (FOV) was assessed. • FOV completion within 5 days of birth hospitalization discharge for Medicaid infants is substantially lower than that of commercially insured infants. • For infants born during the RSV season administration of RSV antibodies in the newborn nursery would ensure optimal uptake. New extended half-life antibodies for the single-dose prevention of medically attended (MA) respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) have been developed for administration to all infants before or during their first RSV season. For infants born during the season, administration as soon as feasible after birth would provide optimal protection and minimize access disparities. The objective of this study was to assess the time from birth hospitalization discharge to the first outpatient visit (FOV) among US infants in order to determine optimal site of administration for the extended half-life antibody. This retrospective, observational, time-to-event analysis uses the Merative™ MarketScan® Commercial and Multi-State Medicaid Databases. Time to FOV is reported separately for the COVID-19 and recent pre-COVID-19 eras and for commercially insured and Medicaid infants. Overall, 73.8 % of Medicaid infants had an FOV within 5 days as compared to 84.7 % of commercially insured infants. Estimates were higher during the COVID-19 era. Urban commercially insured infants had much higher FOV completion than their counterparts. Among Medicaid infants, urban Black and rural White infants were least likely to complete their FOV within 5 days of birth hospitalization discharge. FOV within 5 days after birth hospitalization discharge for Medicaid infants is substantially lower than that of commercially insured infants. Approximately 1 in 4 Medicaid infants and 1 in 8 infants with commercial insurance did not have an outpatient visit within 5 days of birth hospitalization discharge. For US infants born during the RSV season, administration of extended half-life RSV antibodies in the newborn nursery prior to discharge would ensure optimal uptake and minimize access disparities. [ABSTRACT FROM AUTHOR]

BackgroundUnderstanding the safety of vaccines is critical to inform decisions about vaccination. Our objective was to conduct a systematic review of the safety of vaccines recommended for children, adults, and pregnant women in the United States.MethodsWe searched the literature in November 2020 to update a 2014 Agency for Healthcare Research and Quality review by integrating newly available data. Studies of vaccines that used a comparator and reported the presence or absence of key adverse events were eligible. Adhering to Evidence-based Practice Center methodology, we assessed the strength of evidence (SoE) for all evidence statements. The systematic review is registered in PROSPERO (CRD42020180089).ResultsOf 56,603 reviewed citations, 338 studies reported in 518 publications met inclusion criteria. For children, SoE was high for no increased risk of autism following measles, mumps, and rubella (MMR) vaccine. SoE was high for increased risk of febrile seizures with MMR. There was no evidence of increased risk of  intussusception with rotavirus vaccine at the latest follow-up (moderate SoE), nor of diabetes (high SoE). There was no evidence of increased risk or insufficient evidence for key adverse events for newer vaccines such as 9-valent human papillomavirus and meningococcal B vaccines. For adults, there was no evidence of increased risk (varied SoE) or insufficient evidence for key adverse events for the new adjuvanted inactivated influenza vaccine and recombinant adjuvanted zoster vaccine. We found no evidence of increased risk (varied SoE) for key adverse events among pregnant women following tetanus, diphtheria, and acellular pertussis vaccine, including stillbirth (moderate SoE).ConclusionsAcross a large body of research we found few associations of vaccines and serious key adverse events; however, rare events are challenging to study. Any adverse events should be weighed against the protective benefits that vaccines provide.

• In healthy Japanese infants/toddlers, V114 given subcutaneously was well tolerated. • The V114 safety profile was comparable to that of PCV13. • V114 elicited immune responses to all 15 serotypes in healthy infants/toddlers. • V114 was non-inferior for the 13 PCV13 serotypes after the three-dose infant series. • V114-elicited immune responses were higher than PCV13 for serotypes 22F and 33F. This phase III study evaluated safety, tolerability, and immunogenicity of V114 (15-valent pneumococcal conjugate vaccine) in Japanese infants. V114 contains all 13 serotypes in PCV13 plus additional serotypes 22F and 33F. Healthy Japanese infants were randomized to receive three primary doses of V114 or PCV13 (dose 1 at 2–6 months of age; doses 2 and 3 ≥ 27 days after prior dose), plus a toddler dose at 12–15 months of age. Adverse events (AEs) were collected on Days 1–14 following each vaccination. Serotype-specific anti-pneumococcal immunoglobulin G (IgG) was measured 30 days post-dose 3, pre-dose 4, and 30 days post-dose 4. Primary objectives included non-inferiority of V114 to PCV13 for the 13 shared serotypes based on serotype-specific IgG response rates (IgG ≥ 0.35 μg/mL) and geometric mean concentration (GMC) ratios, and for serotypes 22F and 33F based on IgG response rates and compared with the lowest response of any serotype in the PCV13 group, at 30 days post-dose 3. Overall, 694 infants were randomized to V114 (n = 347) or PCV13 (n = 347). Proportions of participants with solicited and serious AEs were comparable between vaccination groups. V114 met non-inferiority criteria for all 13 shared serotypes, based on difference in proportion of responders (lower bound of two-sided 95 % confidence interval [CI] > −10.0) and IgG GMC ratios (V114/PCV13, lower bound of two-sided 95 % CI > 0.5) at 30 days post-dose 3. The non-inferiority criterion based on IgG response rates was met for serotype 22F, but narrowly missed for serotype 33F (90.9 %, lower bound of two-sided 95 % CI −10.6). In Japanese infants, a four-dose series of V114 was generally well tolerated. Compared with PCV13, V114 provided non-inferior immune responses to the 13 shared serotypes and higher immune responses to serotype 22F and 33F post-primary series. Trial registration: ClinicalTrials.gov : NCT04384107; EudraCT 2019-003644-68. [ABSTRACT FROM AUTHOR]

An increased risk of chorioamnionitis in people receiving tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine during pregnancy has been reported. The importance of this association is unclear as additional study has not demonstrated increased adverse infant outcomes associated with Tdap vaccination in pregnancy. We conducted a retrospective observational cohort study of pregnant people ages 15–49 years with singleton pregnancies ending in live birth who were members of 8 Vaccine Safety Datalink (VSD) sites during October 2016–September 2018. We used a time-dependent covariate Cox model with stabilized inverse probability weights applied to evaluate associations between Tdap vaccination during pregnancy and chorioamnionitis and preterm birth outcomes. We used Poisson regression with robust variance with stabilized inverse probability weights applied to evaluate the association of Tdap vaccination with adverse infant outcomes. We performed medical record reviews on a random sample of patients with ICD-10-CM -diagnosed chorioamnionitis to determine positive predictive values (PPV) of coded chorioamnionitisfor "probable clinical chorioamnionitis," "possible clinical chorioamnionitis," or "histologic chorioamnionitis." We included 118,211 pregnant people; 103,258 (87%) received Tdap vaccine during pregnancy; 8098 (7%) were diagnosed with chorioamnionitis. The adjusted hazard ratio for chorioamnionitis in the Tdap vaccine-exposed group compared to unexposed was 0.96 (95% CI 0.90–1.03). There was no association between Tdap vaccine and preterm birth or adverse infant outcomes associated with chorioamnionitis. Chart reviews were performed for 528 pregnant people with chorioamnionitis. The PPV for clinical (probable or possible clinical chorioamnionitis) was 48% and 59% for histologic chorioamnionitis. The PPV for the combined outcome of clinical or histologic chorioamnionitis was 81%. Tdap vaccine exposure during pregnancy was not associated with chorioamnionitis, preterm birth, or adverse infant outcomes. ICD-10 codes for chorioamnionitis lack specificity for clinical chorioamnionitis and should be a recognized limitation when interpreting results. [ABSTRACT FROM AUTHOR]

In January 2020 the UK changed from a 2 + 1 schedule for 13-valent pneumococcal conjugate vaccine (PCV13) to a 1 + 1 schedule (doses at 3 and 12 months) based on a randomized immunogenicity trial comparing the two schedules. Carriage prevalence measured at the time of booster and 6 months later in 191 of the 213 study infants was 57 % (109/191) and 60 % (114/190) respectively. There were eight episodes of vaccine-type (VT) or vaccine-related 6C carriage in the 2 + 1 and six in the 1 + 1 group; ≥4-fold rises in serotype-specific IgG in 71 children with paired post-booster and follow up blood samples at 21–33 months of age were found in 20 % (7/35) of the 2 + 1 and 15 % (6/41) of the 1 + 1 group. VTs identified in carriage and inferred from serology were similar comprising 3, 19A and 19F. Dropping a priming dose from the 2 + 1 PCV 13 schedule did not increase VT carriage in the study cohort. Ongoing population level carriage studies will be important to confirm this. [ABSTRACT FROM AUTHOR]

• ACIP recommends that pregnant women receive Tdap, ideally at 27–36 weeks' gestation. • Tdap5 vaccination during 27–36 weeks' gestation protects infants from pertussis. • Tdap vaccination of mothers after pregnancy did not protect infants from pertussis. To evaluate the effectiveness of the tetanus, diphtheria, and acellular pertussis (Tdap) vaccine containing five pertussis components (Tdap5; Adacel®, Sanofi) when given during pregnancy at preventing pertussis in infants less than 2 months of age. The US Centers for Disease Control and Prevention (CDC), in collaboration with the Emerging Infections Program (EIP) Network, undertook a case-control study evaluating the effectiveness of Tdap vaccination in pregnancy against pertussis in infants less than 2 months of age based on data collected by the EIP Network from 2011 through 2014. The dataset from the CDC/EIP Network study was used to conduct this product-specific vaccine effectiveness analysis of Tdap5 vaccination in pregnancy to prevent disease in young infants. The main outcome of interest was vaccine effectiveness in infants whose pregnant parents were vaccinated with Tdap5 between 27 and 36 weeks' gestation, in accordance with the ideal timing for Tdap vaccination in pregnancy recommended by the US Advisory Committee on Immunization Practices. Odd ratios (ORs) and 95 % confidence intervals (CIs) were estimated using conditional logistic regression, and vaccine effectiveness was calculated as (1–OR) × 100 %. There were 160 infant pertussis cases and 302 matched controls included in this Tdap5-specific study. Tdap5 effectiveness in preventing pertussis in infants whose pregnant parents were vaccinated between 27 and 36 weeks' gestation was 92.5 % (95 % CI, 38.5 %–99.1 %). Effectiveness of Tdap5 against pertussis-related hospitalization in infants whose pregnant parents were vaccinated between 27 and 36 weeks' gestation could not be calculated due to lack of discordance among matched cases and controls. Vaccination of the parents after pregnancy or less than 14 days before delivery did not protect infants from pertussis. Tdap5 vaccination in pregnancy between 27 and 36 weeks' gestation is highly effective at protecting young infants from pertussis. Study registration: ClinicalTrials.gov , NCT05040802. [ABSTRACT FROM AUTHOR]

This phase III study evaluated safety, tolerability, and immunogenicity of V114 (15-valent pneumococcal conjugate vaccine) in healthy infants. V114 contains all 13 serotypes in PCV13 and additional serotypes 22F and 33F. Healthy infants were randomized to two primary doses and one toddler dose (2+1 regimen) of V114 or PCV13 at 3, 5, and 12 months of age; diphtheria, tetanus, pertussis (DTaP), inactivated poliovirus (IPV), Haemophilus influenzae type b (Hib), hepatitis B (HepB) vaccine was administered concomitantly. Adverse events (AEs) were collected on Days 1–14 following each vaccination. Serotype-specific anti-pneumococcal immunoglobulin G (IgG) was measured 30 days post-primary series, immediately prior to toddler dose, and 30 days post-toddler dose. Primary objectives included non-inferiority of V114 to PCV13 for 13 shared serotypes and superiority of V114 to PCV13 for serotypes 22F and 33F. 1191 healthy infants were randomized to V114 (n = 595) or PCV13 (n = 596). Proportions of participants with solicited AEs and serious AEs were comparable between groups. V114 met non-inferiority criteria for 13 shared serotypes, based on difference in proportions with serotype-specific IgG ≥0.35 μg/mL (lower bound of two-sided 95% confidence interval [CI] >−10.0) and IgG geometric mean concentration (GMC) ratios (lower bound of two-sided 95% CI >0.5) at 30 days post-toddler dose. V114 met superiority criteria for serotypes 22F and 33F, based on response rates (lower bound of two-sided 95% CI >10.0) and IgG GMC ratios (lower bound of two-sided 95% CI >2.0) at 30 days post-toddler dose. Antibody responses to DTaP-IPV-Hib-HepB met non-inferiority criteria, based on antigen-specific response rates. A two-dose primary series plus toddler dose of V114 was well-tolerated in healthy infants. Compared with PCV13, V114 provided non-inferior immune responses to 13 shared serotypes and superior immune responses to additional serotypes 22F and 33F. [ABSTRACT FROM AUTHOR]

Vaccination is the most cost-effective action in preventing infectious diseases. Despite Iran's success in high vaccination coverage, in some areas there is a delay in vaccination. The aim of this study was to determine and compare the effect of education on immunization via lecture and film upon parental delay in vaccination uptake for children under 12 months of age. A multicentre cluster-randomized clinical trial with comprehensive urban health centres (CUHCs) in Shooshtar city, Khuzestan province, Iran as the unit of randomization was conducted. Overall, 8 CUHCs were randomized to receive education either via film (n = 165) or lecture (n = 164). In order to assign CUHCs to two groups, a simple random sampling method of coin tossing was used. Parents with children under 12 months and with a history of delayed vaccination were included in the study. Consecutive sampling was performed until the number needed for the cluster was reached. Interventions were delivered in small groups of 5–8 participants. Demographical data and clinical histories were collected from parents directly via a personal characteristic's questionnaire. Clinical data was extracted from vaccination records, the child's vaccine card and the vaccine information registration system. Statistical analyses of intervention effects were performed as per-protocol analysis. In terms of individual characteristics and vaccine information significant differences between the two groups were only observed in relation to the parent of the participant, the child's gender, the number of children in the family, and timely injection of the vaccine in the previous child (p < 0.05). The chance of delay in vaccination after the intervention, without and considering the effect of intervening variables was 78 % and 74 % higher in the lecture group than in the film group, respectively (OR = 1.786, CI = 1.152–2.774 vs AOR = 1.743, CI = 1.011–3.007). Overall, 37.6 % of children in the film-based education group and 51.8 % of children in the lecture-based education group received their next vaccine with a delay of more than 7 days. Education delivered via film can reduce the delay in vaccination more effectively. These findings, along with those of other studies conducted around the world suggest that multimedia education should be considered more widely in the field of education in children's vaccination. [ABSTRACT FROM AUTHOR]

Introduction: Measles vaccination has greatly reduced the disease burden worldwide, but challenges remain due to variations in vaccine effectiveness across age groups. This study aimed to assess the serological profile of measles antibodies across different age groups, evaluate the impact of maternal immunity on antibody levels in infants under 12 months, and assess measles immunity in vaccinated individuals. Material and methods: This cross-sectional study was conducted from June 2022 to January 2023 at the Children's Medical Center, a referral hospital in Iran. Serum samples were tested for measles-specific IgG and IgM antibodies using a commercial enzyme-linked immunosorbent assay (ELSA). An avidity assay was performed to assess measles virus-specific IgG antibodies on the samples that were positive and borderline for the measles IgG ELISA. Results: The study included 969 participants across various age groups. Among them, 23% (221 out of 953) tested positive for measles IgM ELISA, and 52% (504 out of 969) for measles IgG ELISA. Regarding the avidity assay for measles virus-specific IgG, the majority (418 out of 573, 73%) showed high-avidity antibodies. Measles-specific IgG levels varied significantly across different age groups, with infants below 6 months old showing a mean IgG level of 477 mIU/mL, declining to 230 mIU/mL between 6 and 12 months, and increasing significantly to 683 mIU/mL in the 12 to 18 month age group, reaching a peak at 938 mIU/mL among children aged 18–72 months. Conclusion: The increasing IgM positivity among young Iranians suggests a rising risk of measles outbreaks, possibly due to vaccination gaps. Inadequate antibody levels in infants raise concerns about vaccination effectiveness. Considering declining maternal antibodies, vaccinating infants at 6–9 months could be beneficial. Boosters for adolescents and women may further mitigate outbreak risks. [ABSTRACT FROM AUTHOR]

Maternal vaccination with respiratory syncytial virus prefusion F vaccine (RSVpreF) is effective at preventing RSV-associated lower respiratory tract illness (LRTI) in newborns/infants. This subgroup analysis from the global, phase 3, randomized, double-blind, placebo-controlled MATISSE (Maternal Immunization Study for Safety and Efficacy) trial evaluated participants enrolled in Japan. Pregnant women 24–36 weeks' gestation were randomized 1:1 to receive RSVpreF or placebo. Maternal safety endpoints included local reactions/systemic events within 7 days, adverse events (AEs) through 1 month, and serious AEs (SAEs) through 6 months after vaccination. In infants born to maternal participants, safety endpoints included specific birth outcomes, AEs through 1 month after birth, and SAEs and newly diagnosed chronic medical conditions through 12 or 24 months after birth. Vaccine efficacy in infants was assessed against RSV-positive, medically attended LRTI (RSV-MA-LRTI) and severe RSV-MA-LRTI through 180 days after birth. In Japan, 230 maternal participants received RSVpreF and 232 received placebo; 218 and 216 infants born to these mothers, respectively, were analyzed. Observed vaccine efficacy (95 % CIs) against infant RSV-MA-LRTI within 90 and 180 days after birth was 100.0 % (30.9, 100.0; RSVpreF, 0 cases; placebo, 7 cases) and 87.6 % (7.2, 99.7; RSVpreF, 1 case; placebo, 8 cases), respectively. Vaccine efficacy (95 % CIs) against severe RSV-MA-LRTI within 90 and 180 days was 100.0 % (−140.9, 100.0; RSVpreF, 0 cases; placebo, 3 cases) and 75.1 % (−151.5, 99.5; RSVpreF, 1 case; placebo, 4 cases), respectively. No safety concerns were identified. AE rates ≤1 month after vaccination/birth were similar in the RSVpreF (maternal, 16.1 %; infant, 48.6 %) and placebo (19.8 %; 50.5 %) groups. Preterm birth rates were also similar (RSVpreF, 3.2 %; placebo, 6.0 %). Safety and efficacy data in Japanese participants were consistent with overall MATISSE results, supporting the efficacy of maternal RSVpreF vaccination against severe MA-RSV-LRTI/MA-RSV-LRTI in infants, with no safety concerns. NCT04424316. [ABSTRACT FROM AUTHOR]

BackgroundMeasles is a significant contributor to child mortality in the Democratic Republic of the Congo (DRC), despite routine immunization programs and supplementary immunization activities (SIA). Further, national immunization coverage levels may hide disparities among certain groups of children, making effective measles control even more challenging. This study describes measles vaccination coverage and reporting methods and identifies predictors of vaccination among children participating in the 2013-2014 DRC Demographic and Health Survey (DHS).MethodsWe examined vaccination coverage of 6947 children aged 6-59 months. A multivariate logistic regression model was used to identify predictors of vaccination among children reporting vaccination via dated card in order to identify least reached children. We also assessed spatial distribution of vaccination report type by rural versus urban residence.ResultsUrban children with educated mothers were more likely to be vaccinated (OR = 4.1, 95% CI: 1.6, 10.7) versus children of mothers with no education, as were children in wealthier rural families (OR = 2.9, 95% CI: 1.9, 4.4). At the provincial level, urban areas more frequently reported vaccination via dated card than rural areas.ConclusionsResults indicate that, while the overall coverage level of 70% is too low, socioeconomic and geographic disparities also exist which could make some children even less likely to be vaccinated. Dated records of measles vaccination must be increased, and groups of children with the greatest need should be targeted. As access to routine vaccination services is limited in DRC, identifying and targeting under-reached children should be a strategic means of increasing country-wide effective measles control.

Pertussis vaccination (Tdap -Tetanus-diphtheria-acellular pertussis) for pregnant women has been recommended since November 2017 in Singapore. In this prospective test-negative case-control study from 2018 to 2019, we aimed to evaluate vaccine effectiveness (VE) against pertussis infection and pertussis-related intensive care unit (ICU) admission according to Tdap (Tetanus-diphtheria-acellular pertussis) during pregnancy and/or infant pertussis vaccination. A total of 58 children (26 cases, 32 controls) were recruited with 4 ICU admissions. The median age was 3 months (interquartile range [IQR] 1.50–4.56 months). Overall, 25.9 % of mothers had received antenatal Tdap vaccination and 43.1 % of infants received pertussis vaccination, majority only 1 dose. Tdap in pregnancy alone without infant vaccine or with 0–1 infant dose had a VE of 97.62 % (95 % confidence interval [CI] 53.25–99.88 %), 98.17 % (95 %CI 66.61–99.9 %) respectively, against pertussis infection and 71.9 % (95 %CI 0.0–98.64), 75.86 % (95 % CI 0.0–98.78) respectively, against ICU admissions. Conclusion: Maternal Tdap vaccination was highly protective against infant pertussis and should be routinely recommended for all pregnant women. [ABSTRACT FROM AUTHOR]

Background: In response to the challenge of maintaining COVID-19 vaccination coverage amidst the pandemic, VillageReach, in collaboration with the Ministry of Public Health Prevention and Hygiene in Kinshasa, DRC, integrated COVID-19 vaccination with routine immunization services at two primary healthcare facilities. This initiative, launched in July 2022, represented the first of its kind in the DRC, aiming to assess the effectiveness and scalability of a multimodal vaccination approach., Methods: Through a rapid appraisal involving key informant interviews and analysis of pre- and post-integration service delivery data, this case study explores the operational dynamics and outcomes of integrating COVID-19 and routine immunizations., Results: Results demonstrated that the integrated approach not only maintained COVID-19 vaccine coverage but also significantly enhanced routine immunization uptake, particularly among under-immunized and zero-dose children. Overall, the vaccination sites, outreach, and integrated health facilities administered 229,983 (33 %) of COVID-19 vaccines in Kinshasa, of which 53 % were referred by community health workers. Additionally, 998 under-immunized children received routine immunizations, of whom 126 were zero-dose children. Key success factors included sustained community health worker engagement, neighborhood-specific strategies, accessible vaccination points, and robust data management. The findings suggest that such integrative strategies can effectively bolster immunization coverage in urban poor communities, offering valuable insights for similar initiatives in the DRC and beyond., Conclusion: This study advocates for sustained investment in innovative immunization models to strengthen primary healthcare systems post-pandemic., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The SARS-COV2 pandemic caused significant disruptions in immunization delivery. Baseline deficit gaps in immunization completion exacerbated ongoing disparities in immunization coverage in low- and middle-income. Emerging reports focused on global strategies for return to routine immunization schedules. Currently, there are no studies that examined the dual challenge of returning to normal immunization in a conflict-recovery setting, such as the ISIS (Islamic State of Iraq and Syria) occupation of Iraq post-COVID-19 pandemic. The objective of this study was to estimate the number of children in Hadeetha, Iraq from 12 to 24 months of age who continued to be lost to the routine immunization schedule due to the COVID-19 pandemic shutdowns. Random sampling occurred from a compiled district health facility registrar of all children in the target birth cohort who had a 12-month immunization scheduled during the 2020 lockdown and were lost to the immunization schedule. A total of 171 households from the sampling frame were included in the final sample. In this cross-sectional study, survey data was collected on the head of the household, the caregiver and the child. Additional questions assessed vaccine hesitancy, vaccine information trusted sources and COVID-19 impact on healthcare access. A risk factor analysis was applied to assess using Chi-square (Χ 2 ) for predictors of lack of DTP3 (Diphtheria, Tetanus and Polio) third dose completion. Of children in the study, 67.3 % did not complete the 6-antigen series at 12-months of age and 46.2 % were missing DTP3 for vaccines to be completed during the pandemic shutdown. Specific risk factors for lack of immunization for the DTP3 vaccine included area of residence, age and caregiver knowledge of vaccines. Respondents indicated a dependence on mass vaccination campaigns but also indicated a willingness to receive phone reminders and television campaigns about vaccination schedules., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Sara Al-Dahir reports a relationship with Pfizer Inc. that includes: funding grants. Sara Al-Dahir reports a relationship with Genentech Inc. that includes: funding grants. Kawsar Talaat reports a relationship with Pfizer that includes: funding grants. Kawsar Talaat reports a relationship with AstraZeneca Pharmaceuticals LP that includes: funding grants. Kawsar Talaat reports a relationship with Moderna Inc. that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Cameroon, a country in sub-Saharan Africa, ranks among the top 15 countries worldwide with the highest number of zero-dose (unvaccinated) children. Among other reasons, pockets of hard-to-reach communities that traditionally miss essential healthcare services, including childhood immunization, largely contribute to this sub-optimal vaccination coverage. This is the case of Manoka Health District (MHD), an archipelago district with a zero-dose proportion of 91.7%. High disease burdens such as malaria and water-borne diseases have forced the population to depend on herbalists and roadside drug vendors, eroding trust in the primary healthcare system and worsening vaccine hesitancy. This study, therefore, aims to describe how a project optimized vaccine demand generation in these hard-to-reach settlements using an integrated community health worker service delivery package developed using the Community-oriented primary healthcare (COPC) model., Methodology: This cross-sectional descriptive study was based on data collected from November 2021 to August 2022 in three project-implementing health areas (Kombo Moukoko, Kooh, and Toube) in the Manoka health district. Data was collected on the integrated health packages offered by Community Health Workers (CHWs). It comprised health education on malaria and water-borne diseases, screening for malaria using Rapid Diagnostic Test (RDT), treatment of under-5 for uncomplicated malaria and diarrhea, conduct of essential Antenatal Care (ANC) services, and vaccination counseling and referral in the three health areas. Microsoft Excel 2013 was used to analyze descriptive data and expressed results as percentages, with tables and column charts used for data visualization. All missing data were considered in the final analysis., Results: Over 550 under-5 children and 187 pregnant women were identified to be in need of curative and preventive care services during the project period. About 81% of pregnant women received a minimum ANC package by CHWs, and 47% adhered to referrals to health facilities for continuous ANC and delivery. Half of the children under 5 with health issues were diagnosed and managed for uncomplicated malaria. Also, during home visits, 617 under-immunized and zero-dose children less than two years of age were identified, referred, and vaccinated either during an outreach program or at the nearest health post in a neighboring health area, representing about 64% (617/964) of under-2 children identified in these communities. There was a gradual increase from 0% vaccine acceptance post-referral in the first month to 47% after six months and 64% at one year of intervention., Conclusion: The use of the COPC model to co-develop integrated essential health service packages that meet the needs of communities showed value in building trust and increasing childhood immunization uptake in hard-to-reach communities., Competing Interests: Declaration of competing interest Authors declare that there are no conflict of interest pertaining to the study “The use of Community-Oriented Primary Care (COPC) model to generate vaccine demand: The case of a remote fishing community in Cameroon.”, (Copyright © 2024. Published by Elsevier Ltd.)

Background: Kenya introduced Synflorix™ (GlaxoSmithKline, PCV10-GSK), a 10-valent pneumococcal conjugate vaccine, in 2011, using three primary doses and, in select areas, catch-up campaigns. Surveys conducted 1-2 years post-introduction showed a stable prevalence of pneumococcal colonization, with declines in vaccine-type carriage. However, little is known about the long-term impact of PCV10-GSK in Kenya., Methods: We conducted a cross-sectional survey of pneumococcal carriage among children aged <5 years in November-December 2017 in Kibera (Nairobi informal settlement, no catch-up) and Asembo (rural western Kenya, 2-dose catch-up for children 1-4 years), using the same methods and settings as prior annual surveys from 2009 to 2013. Participants were randomly selected from an ongoing population-based surveillance platform. Nasopharyngeal swabs were frozen in skim milk-tryptone-glucose-glycerin media within 4 h and underwent culture with broth enrichment for pneumococcus. Isolates were serotyped by polymerase chain reaction and Quellung., Results: We enrolled 504 children, including 252 from each site; >90 % of participants had received 3 doses of PCV10-GSK. Pneumococcal colonization was detected in 210 (83.3 %) participants in Kibera and 149 (59.1 %) in Asembo, which was significantly lower than the prevalence observed in 2013 (92.9 % and 85.7 %, respectively). PCV10-GSK serotypes were detected in 35/252 (13.9 %) participants in Kibera and 23/252 (9.1 %) in Asembo, respectively; these prevalences were lower, but not statistically different, from vaccine-type carriage prevalences in 2013 (17.3 % and 13.3 %, respectively). In 2017 in both sites, serotypes 3, 6A, 19A, 19F, and 35B were among the most common serotypes., Conclusion: Six years post-PCV10-GSK introduction, the prevalence of pneumococcal carriage among children has decreased, and the impact of PCV10-GSK on vaccine-type carriage has plateaued. Kenya recently changed from PCV10-GSK to Pneumosil™ (Serum Institute of India), a 10-valent PCV that includes serotypes 6A and 19A; these data provide historical context for interpreting changes in vaccine-type carriage following the PCV formulation switch., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: Humoral immune response against the pre-fusion (pre-F) conformation of respiratory syncytial virus (RSV) F protein has been proposed to play a protective role against infection. An RSV pre-F maternal vaccine has been recently approved in several countries to protect young infants against RSV. We aimed to assess serum IgG titers against the pre-F and post-F conformations of RSV F protein and their association with life-threatening RSV disease (LTD) in previously healthy infants., Methods: A prospective cohort study including hospitalized infants <12 months with a first RSV infection was conducted during 2017-2019. Patients with LTD required intensive care and mechanical respiratory assistance. RSV pre-F exclusive and post-F antibody responses were determined by post-F competition and non-competition immunoassays, respectively, and neutralizing activity was measured by plaque reduction neutralization test., Results: Fifty-eight patients were included; the median age was 3.5 months and 41 % were females. Fifteen patients developed LTD. RSV F-specific antibody titers positively correlated with neutralizing antibody titers in acute and convalescent phases but, importantly, they did not associate with LTD. Acute RSV pre-F exclusive and post-F IgG titers negatively correlated with patient age (P = 0.0007 and P < 0.0001), while a positive correlation was observed between the fold changes in RSV F-specific antibody titers between convalescent and acute phase and patient age (P = 0.0014 and P < 0.0001). Infants ≤2 months exhibited significantly lower fold-changes in RSV F-specific and neutralizing antibody titers between convalescence and acute phase than older infants. Additionally, acute RSV antibody titers showed no correlation with nasal RSV load and, furthermore, nasal viral load was not associated with the development of LTD., Conclusions: This study highlights that protection against life-threatening RSV disease is not necessarily antibody-dependent. Further characterization of the immune response against RSV and its role in protection against severe disease is important for the development of the safest possible preventive strategies., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Fausto Martin Ferolla reports financial support was provided by Thrasher Research Fund, United States. Eduardo Luis Lopez reports financial support was provided by Fundacion Argentina de Infectologia Pediatrica. Barney S Graham has patent #WO2014160463A1 Prefusion RSV F proteins and their use licensed to Assignee. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: This paper highlights recent clinical complications of mumps reported in the United States and summarizes appropriate confirmatory testing for mumps, encouraging vigilance for mumps disease, an endemic vaccine-preventable illness., Methods: Surveillance data from jurisdictions reporting confirmed and probable cases of mumps in the United States were descriptively analyzed to assess epidemiologic trends from January 1, 2018 - December 31, 2023. Data were reported to the National Notifiable Disease Surveillance System and the Epidemiology and Laboratory Capacity Project O. Cases were classified according to the Council of State and Territorial Epidemiologists 2011 mumps case definition., Results: From 2018-2023, United States health departments reported 8,006 confirmed and probable mumps cases to the National Notifiable Disease Surveillance System, of which 85.4% occurred during January 1, 2018-April 4, 2020 and 14.6% during April 5, 2020-December 31, 2023. The incidence of mumps was highest among those aged 18-24 years during 2018-2020 (maximum of 4.54 cases per 100,000 persons in 2019), and highest among those aged 1-4 years during 2021-2023 (maximum 0.67 per 100,000 persons in 2023). Incidence among all age groups during 2021-2023 remained below levels during 2018-2020. Fewer than 12% of mumps cases were confirmed during 2021-2023, compared to >50% during 2018-2019., Conclusions: Although incidence has declined since the COVID-19 pandemic, these surveillance data highlight that mumps remains endemic in the United States. Therefore, maintaining high MMR vaccination coverage is essential to prevent future vaccine-preventable outbreaks and minimize severe complications from infection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: Effective strategies are needed to improve vaccine acceptance. This study sought to determine if a peer-led vaccine education intervention embedded within community medical practices increases parental acceptance of pediatric pneumococcal conjugate vaccination., Methods: From March 2022-July 2023, we conducted a randomized trial at three pediatric health practices in predominantly Hasidic Jewish neighborhoods in New York, where vaccine deferral is common. Parents of children up to 18 months due/overdue for routine pneumococcal vaccination were randomized (1:1) to receive routine care alone or routine care plus a peer educational intervention. Peer educators trained in motivational interviewing and vaccine science provided counseling at enrollment and follow-up telephone engagement in the intervention arm at day 30 and 60. Primary outcome was child's pneumococcal immunization status by allocation arm expressed as at least one dose received between enrollment and 90 days post-enrollment., Results: 144 parent-child dyads were eligible for outcome analysis. Participants in the group receiving routine care along with peer-led vaccine counseling were significantly more likely to have their child receive at least 1 vaccine dose between enrollment and 90 days compared to the group who received routine care alone (28.4 % vs 12.9 %, risk ratio [RR] 2.21, confidence interval [CI] 1.09-4.49, p = 0.022). The effect of peer education was greatest in dyads with children less than 1 year old at enrollment (34 % vs 12.7 %, RR 2.67, CI (1.22-5.86), p = 0.009)., Conclusions: Peer vaccine education can increase vaccine acceptance compared to routine care alone and may be particularly valuable in decreasing vaccination delays for younger infants. (Funded by EGL Charitable Foundation, ClinicalTrials.gov NCT05875779)., Competing Interests: Declaration of competing interest The authors have no relevant conflicts of interest to disclose., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Amid the global response to the COVID-19 pandemic, Cambodia emerges as a notable exemplar, boasting a remarkable vaccination rate of 91% of its population by the end of 2021. This success can be attributed to a multifaceted approach encompassing strong governmental leadership, robust vaccine management, and effective risk communication. Despite notable success, challenges persisted in reaching unvaccinated segments of the population. Rapid Coverage and Community assessments (RCCAs) supported by UNICEF were deployed in 2022 and 2023 to support Government efforts in expanding vaccination reach to missed populations and bolster COVID-19 booster doses. RCCAs were conducted across 8 provinces, assessing 13,547 individuals from 87 low-coverage communes to identify not vaccinated people and understand their barriers. Overall, only seven percent missed any dose of C-19 vaccine, Disabilities and lack of education correlated with higher rates of zero doses (20.8% and 17.8%, respectively), with concerns about personal health conditions (25%) and adverse effects (10%) cited as top reasons for non-vaccination. RCCAs, differing from routine monitoring, utilized purposive sampling to identify barriers to vaccine access and uptake. Findings informed adaptive strategies by government and partners to enhance outreach in low-coverage areas. The RCCAs played a crucial role at the local level in ensuring vaccinations reached overlooked populations, providing innovative solutions and supporting UNICEF's national strategies. By the end of 2022, Cambodia achieved a high subnational coverage, contributing to a national coverage of 95% for primary doses and nearly 70% for the first booster for everyone above three years old. RCCAs also fostered local coordination, facilitating resource sharing, and coordinated action for more effective local outreach and community trust. Integration of RCCAs into national immunization programs is recommended to develop targeted outreach for underserved populations, including zero-dose children and communities. Cambodia's adaptation of RCCAs during the pandemic offers valuable insights into identifying and engaging missed populations, highlighting the importance of community involvement and targeted interventions for future pandemic preparedness, and achieving more equitable health outcomes in the longer-term., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Some public health professionals have expressed concern that the COVID-19 pandemic has increased vaccine hesitancy about routine childhood vaccines; however, the differential prevalence of vaccine hesitancy about specific vaccines has not been measured., Methods: Data from the National Immunization Survey-Child COVID-19 Module (NIS-CCM) were analyzed to assess the proportion of children ages 6 months-17 years who have a parent with hesitancy about: COVID-19, influenza, human papillomavirus (HPV) (for children ≥ 9 years) vaccines, and "all other childhood shots." Interviews from October 2022 through April 2023 were analyzed., Results: The percentage of children with a vaccine-hesitant parent varied by vaccine. 55.9% of children had a parent hesitant about COVID-19 vaccine, 30.9% hesitant about influenza vaccine, 30.1% hesitant about HPV vaccine, and 12.2% had a parent hesitant about other vaccines such as measles, polio, and tetanus., Conclusion: The study findings suggest that differential interventions and communications to parents be used to educate about COVID-19, influenza, HPV, and routine childhood vaccinations because the hesitancy levels differ widely., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: Nirsevimab is an extended half-life monoclonal antibody (mAb) licensed for the prevention of respiratory syncytial virus (RSV)-associated lower respiratory tract disease in neonates, infants and medically vulnerable children. We characterized RSV isolates recovered from participants enrolled in MEDLEY: a randomized, palivizumab-controlled phase 2/3 trial of nirsevimab in infants born preterm and/or with congenital heart disease or chronic lung disease of prematurity., Methods: Participants were assessed in two RSV seasons (Season 1 and 2). Season 1 participants were randomized (2:1) to receive a single dose of nirsevimab (50 mg if weight <5 kg or 100 mg if weight ≥5 kg in Season 1; 200 mg in Season 2) followed by four monthly doses of placebo, or five once-monthly doses of palivizumab (15 mg/kg weight per dose). Season 2 participants continued nirsevimab and placebo (nirsevimab/nirsevimab) or were re-randomized (1:1) to switch to nirsevimab (palivizumab/nirsevimab) or continue palivizumab (palivizumab/palivizumab). Cases of RSV infection were identified by central testing of nasal swabs from participants seeking medical attention for respiratory illnesses. Nirsevimab and palivizumab binding site substitutions were assessed via microneutralization assay., Results: Twenty-five cases of confirmed RSV infection were observed during the trial and sequenced: 12 in nirsevimab recipients and 10 in palivizumab recipients during Season 1, and 1 case in each Season 2 group. Molecular sequencing of RSV A (n = 14) isolates detected no nirsevimab binding site substitutions, and 3 palivizumab neutralization-resistant substitutions (Lys272Met, Lys272Thr, Ser275Leu). The nirsevimab binding site Ile206Met:Gln209Arg and Ile206Met:Gln209Arg:Ser211Asn substitutions were the only anti-RSV mAb binding site substitutions detected among RSV B isolates (n = 11). Nirsevimab neutralized all nirsevimab and palivizumab binding site substitutions in RSV A and B isolates recovered from MEDLEY participants., Conclusion: No binding site substitution detected during MEDLEY affected RSV susceptibility to nirsevimab neutralization., Competing Interests: Declaration of competing interest Kevin M. Tuffy, Bahar Ahani, Hong Ji, Vaishali S. Mankad, Ulrika Wählby Hamrén, Tonya Villafana, Yingyi Wang and Deidre Wilkins are current employees of AstraZeneca and may hold AstraZeneca stock or stock options. Elizabeth J. Kelly is a former employee of AstraZeneca and a current employee of Sanofi and may hold stock or stock options for both institutions. Ulrika Wählby Hamrén, Tonya Villafana and Deidre Wilkins are named inventors on patents planned, issued or pending related to nirsevimab. Joseph B. Domachowske has received funding to their institution for the conduct of clinical trials from AstraZeneca, Merck and Regeneron, honoraria from Sanofi and has participated in advisory boards for GSK and Sanofi. Kenji Furuno has received honoraria from AstraZeneca and AbbVie. Shabir A. Madhi has received funding from AstraZeneca, Novavax, Providence, Gritstone and ImmunityBio for the conduct of clinical trials; institutional grants from the Bill and Malinda Gates Foundation, GSK, Pfizer and Minervax, honoraria from GSK and MSD and is a member of Data Safety Monitoring Boards for PATH and CAPRISA., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: There are known disparities in U.S. COVID-19 vaccination but there is limited information on national vaccine uptake in a large, racially diverse, all-age population. Here, we describe COVID-19 vaccination coverage in a large U.S. population accessing care in OCHIN (not an acronym), a national network of community-based healthcare organizations., Methods: Within OCHIN, we identified patients aged 6 months and older with ≥1 completed clinical encounter since becoming age-eligible for the COVID-19 vaccine between December 13, 2020 and December 31, 2022. Patients' COVID-19 vaccination status was assessed from OCHIN's Epic® electronic health record which includes data from state immunization information systems. Patients were considered vaccinated if they received ≥1 dose of a monovalent vaccine product; coverage was categorized by age groups (6 months-4 years; 5-11 years, 12-15 years, 16+ years). Multivariate analyses assessed factors associated with COVID-19 vaccination across age groups., Results: The cohort included 3.3 million Hispanic (37 %), non-Hispanic (NH) White (31 %), NH Black (15 %), and NH Asian (7 %) patients; 45 % of whom were Medicaid-enrolled, 19 % uninsured, and 53 % with a household income below 100 % of the federal poverty level. The proportion with ≥1 COVID-19 vaccine dose increased with age, from 11.7 % (6 months through 4 years) to 72.3 % (65 years and older). The only factors associated with significantly higher COVID-19 vaccine coverage across age groups were prior receipt of an influenza vaccine and having private insurance. In adjusted modeling, when compared to NH whites, COVID-19 vaccine coverage was significantly higher among Hispanic, NH Asian, and NH multiple-race patients aged ≥5 years and significantly lower among NH Black and NH Native Hawaiian/Other Pacific Islander patients aged 6 months-4 years old., Conclusions: We identified disparities in primary series COVID-19 vaccine coverage by age, race and ethnicity, household income, insurance status, and prior influenza vaccination within this large, diverse population accessing care in community-based healthcare organizations., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Bradley Crane reports a relationship with Centers for Disease Control and Prevention that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Frances Biel reports financial support was provided by Centers for Disease Control and Prevention. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Joanna Georgescu reports financial support was provided by Centers for Disease Control and Prevention. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Holly Groom reports financial support, administrative support, and statistical analysis were provided by Centers for Disease Control and Prevention. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Allison Naleway reports financial support was provided by Centers for Disease Control and Prevention. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Ning Smith reports financial support was provided by Centers for Disease Control and Prevention. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Evelyn Sun reports financial support was provided by Centers for Disease Control and Prevention. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Teresa Schmidt reports financial support was provided by Centers for Disease Control and Prevention. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Pneumococcus is a common cause of pneumonia, meningitis, and other serious infections in children. The previous study has proved that the 13-valent pneumococcal conjugate vaccine (PCV13) has sufficient immunogenicity in children. The data on long-term persistence of immunity will help the follow-up development work of pneumococcal vaccines., Methods: Children who received the full vaccination course of the tested PCV13 in the previous clinical trial were enrolled again, and these who received other pneumococcal vaccines, or were infected with one or more serotypes of S. pneumoniae corresponding to PCV13 before enrollment were excluded. Participants were divided into four groups by age which is same as that of previous trial. The study lasted for 5 years, during which we measured pneumococcal antibodies of 13 serotypes included in PCV13 at particular points in time. Geometric mean concentrations (GMCs) and seropositive rates (the rate of IgG concentration ≥0.35 μg/mL) of antibodies against 13 serotypes were calculated., Results: For the participants aged 2 months, five years after primary vaccination, except for serotypes 3 and 4, seropositive rates were 100%. GMCs of IgG antibodies against 13 serotypes ranged from 0.733 to 15.160 μg/mL. All of the participants aged 7-11 months had the serotype-specific IgG concentration ≥0.35 μg/mL four years after primary vaccination with the exception of serotypes 3, 4, 6 A and 9 V. IgG GMCs were 0.753-11.031 μg/mL. All participants aged 12-23 months and 2-5 years old had the serotype-specific IgG concentration ≥0.35 μg/mL three or two years after primary vaccination respectively, except for serotype 3. IgG GMCs ranged from 0.815 to 13.111 μg/mL, and 0.684 to 12.282 μg/mL respectively., Conclusion: PCV13 was applied to the population aged 2 months and 7 months - 5 years old with a good immune persistence, providing more extensive evidence of long-term efficacy for that vaccine., Trial Registration: The trial was registered with ClinicalTrials.gov, number NCT06210737., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Routine childhood vaccination is a crucial component of public health in Canada and worldwide. To facilitate catch-up from the global decline in routine vaccination caused by the COVID-19 pandemic, and toward the ongoing pursuit of coverage goals, vaccination programs must understand barriers to vaccine access imposed or exacerbated by the pandemic. We conducted a regionally representative online survey in January 2023 including 2036 Canadian parents with children under the age of 18. We used the COM-B model of behaviour to examine factors influencing vaccination timeliness during the pandemic. We assessed Capability with measures of vaccine understanding and decision difficulty, and Motivation with a measure of vaccine confidence. Opportunity was assessed through parents' self-reported experience with barriers to vaccination. Twenty-four percent of surveyed parents reported having missed or delayed one of their children's scheduled routine vaccinations since the beginning of the pandemic, though most parents reported having either caught up or the intention to catch up soon. In the absence of opportunity barriers, motivation was associated with timely vaccination for children aged 0-4 years (aOR = 1.81, 95 % CI: 1.14-2.84). However, experience with one or more opportunity barriers, particularly clinic closures and difficulties getting an appointment, eliminated this relationship, suggesting perennial and new pandemic-associated barriers are a critical challenge to vaccine coverage goals in Canada., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Globally, migrant populations usually experience lower vaccine coverage than the general population. In Finland, the MMR vaccination coverage of Somalis has not been studied specifically, but existing evidence suggests that the MMR vaccination coverage is high. The aim of this study was to examine both vaccination coverage of Somali children and factors associated with the MMR vaccine uptake of Somali children living in Finland., Methods: Twenty-seven mothers and seventeen public health nurses were interviewed using a semi-structured interview protocol. Audio-recorded interviews were transcribed and translated and analysed thematically after coding. The personal identity code of Somali children born in 2015 and 2020 were extracted from the Population Information System (PIS), and their vaccination coverage data was extracted from the national vaccination register (NVR) to calculate MMR vaccination coverage for Somali children., Results: 96 % of Somali children born in 2015 and 81 % of those born in 2020 received their MMR vaccination. In contrast, the national average MMR vaccine uptake for children born in 2015 was 95 %, while 94 % of those born in 2020 were vaccinated against MMR. Somali mothers had poor knowledge of the MMR vaccine and the diseases it protects against. Trust towards the Finnish healthcare system, perceived benefits of vaccinating, positive attitudes towards vaccines, nurses' systematic approach to vaccine introduction, and nurses taking into account the cultural background of the clients were recognised as enablers positively affecting MMR vaccination uptake., Conclusion: Despite limited knowledge of vaccines, Somali immigrant mothers believe in the benefits of vaccination, and they displayed strong trust towards public health nurses. Further investigation is needed to understand why MMR vaccination coverage has declined among the younger Somali population., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Despite the substantial global impact of influenza, there are limited economic data to guide influenza vaccination programs investments in middle-income countries. We measured the costs of influenza and the costs of an influenza vaccination program in Armenia, using a societal perspective., Methods: During December 2022 through March 2023, retrospective cost data were collected from case-patients and healthcare providers through structured questionnaires at 15 healthcare facilities selected through stratified sampling. Medical costs included medications, laboratory costs, laboratory and diagnostic tests, and routine health care service costs and direct and indirect societal costs were included. Vaccination program costs from the 2021-2022 influenza season were identified using accounting records and categorized as: planning, distribution, training, social mobilization and outreach, supervision and monitoring, procurement, and national- and facility-level administration and storage., Results: The mean costs per episode for SARI and ILI case-patients were $US 823.6 and $US 616.57, respectively. Healthcare service costs were the largest direct expenses for ILI and SARI case-patients. Total costs of the 2021-2022 influenza vaccination program to the government were $US 4,353,738, with the largest costs associated with national- and facility-level administration and storage (30% and 65% respectively). The total cost per dose administered was $US 25.61 ($US 7.73 per dose for procurement and $US 17.88 for the marginal administration cost per dose)., Conclusions: These data on the costs of seasonal influenza prevention programs and the societal costs of influenza illness in Armenia may inform national vaccine policy decisions in Armenia and may be useful for other middle-income countries. Influenza vaccines, like other vaccine programs, are recognized as substantially contributing to the reduction disease burden and associated mortality and further driving economic growth. However, a formal cost-effectiveness analysis should be performed once burden of disease data are available., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: In 2019, following a large outbreak of typhoid fever, the Zimbabwe Ministry of Health and Child Care conducted a typhoid conjugate vaccine (TCV) vaccination campaign in nine high-risk suburbs of Harare. We aimed to evaluate TCV vaccination coverage, vaccine perceptions, and adverse events reported after vaccination., Methods: We conducted a two-stage cluster survey to estimate vaccination coverage in the campaign target areas among children aged 6 months-15 years and to classify coverage as either adequate (≥75 % coverage) or inadequate (<75 % coverage) among adults aged 16-45 years in one suburb. Questionnaires assessed socio-demographic factors, TCV vaccination history, reasons for receiving or not receiving TCV, adverse events following immunization, and knowledge and attitudes regarding typhoid and TCV., Results: A total of 1,917 children from 951 households and 298 adults from 135 households enrolled in the survey. Weighted TCV coverage among all children aged 6 months-15 years was 85.3 % (95 % CI: 82.1 %-88.0 %); coverage was 74.8 % (95 % CI: 69.4 %-79.5 %) among children aged 6 months-4 years and 89.3 % (95 % CI: 86.2 %-91.7 %) among children aged 5-15 years. Among adults, TCV coverage was classified as inadequate with a 95 % confidence interval of 55.0 %-73.1 %. Among vaccinated persons, the most reported reason for receiving TCV (96 % across all age groups) was protection from typhoid fever; the most common reasons for non-vaccination were not being in Harare during the vaccination campaign and not being aware of the campaign. Adverse events were infrequently reported in all age groups (10 %) and no serious events were reported., Conclusions: The 2019 TCV campaign achieved high coverage among school-aged children (5-15 years). Strategies to increase vaccination coverage should be explored for younger children as part of Zimbabwe's integration of TCV into the routine immunization program, and for adults during future post-outbreak campaigns., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: During November 2019-October 2021, a pediatric influenza vaccination demonstration project was conducted in four sub-counties in Kenya. The demonstration piloted two different delivery strategies: year-round vaccination and a four-month vaccination campaign. Our objective was to compare the costs of both delivery strategies., Methods: Cost data were collected using standardized questionnaires and extracted from government and project accounting records. We reported total costs and costs per vaccine dose administered by delivery strategy from the Kenyan government perspective in 2021 US$. Costs were separated into financial costs (monetary expenditures) and economic costs (financial costs plus the value of existing resources). We also separated costs by administrative level (national, regional, county, sub-county, and health facility) and program activity (advocacy and social mobilization; training; distribution, storage, and waste management; service delivery; monitoring; and supervision)., Results: The total estimated cost of the pediatric influenza demonstration project was US$ 225,269 (financial) and US$ 326,691 (economic) for the year-round delivery strategy (30,397 vaccine doses administered), compared with US$ 214,753 (financial) and US$ 242,385 (economic) for the campaign strategy (25,404 doses administered). Vaccine purchase represented the largest proportion of costs for both strategies. Excluding vaccine purchase, the cost per dose administered was US$ 1.58 (financial) and US$ 5.84 (economic) for the year-round strategy and US$ 2.89 (financial) and US$ 4.56 (economic) for the campaign strategy., Conclusions: The financial cost per dose was 83% higher for the campaign strategy than the year-round strategy due to larger expenditures for advocacy and social mobilization, training, and hiring of surge staff for service delivery. However, the economic cost per dose was more comparable for both strategies (year-round 22% higher than campaign), balanced by higher costs of operating equipment and monitoring activities for the year-round strategy. These delivery cost data provide real-world evidence to inform pediatric influenza vaccine introduction in Kenya., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: Catch-up vaccination is a personalised process through which children with missing recommended vaccinations or incomplete vaccination records are brought up to date with the Australian vaccination schedule. Navigating childhood catch-up vaccination can be difficult for migrant parents with inadequate health system knowledge and competing priorities during settlement. This study aimed to understand the experiences of migrant parents with childhood catch-up vaccination and co-design an intervention to improve the process., Methods: We recruited migrant parents who had attended the City of Melbourne Immunisation Service in Melbourne, Australia to participate in a qualitative co-design study between June and August 2022. Expression of interest emails were sent by the service, and we recruited eligible participants. In Phase One, we conducted group interviews with parents to understand their experiences and preferences for an intervention, these were analysed using inductive and framework analysis. In Phase Two, we designed prototype interventions based on parents' preferences and suggestions. In Phase Three, parents shared their feedback on each prototype., Results: Fourteen migrant parents participated in the study. Most parents did not discover the need for catch-up vaccination until childcare or kindergarten enrolment. The lack of information received about vaccination requirements and difficulty navigating the health system made the process challenging and time-consuming. Based on these Phase One themes, we designed a printout, mobile application, and website prototype. All three were well-received in Phase Three. Overall, parents' top three considerations for any intervention were 1) digital and online accessibility, 2) inclusion of step-by-step processes outlining catch-up vaccination; and 3) inclusion of a checklist., Conclusions: Migrant parents lack information about childhood catch-up vaccination in Australia. A relatively simple intervention could help parents more easily navigate the process, thereby saving time and stress. The next steps are to seek funding to pilot such an intervention to assess practicality and usefulness., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: JT is an investigator on a project grant sponsored by Industry. Her institution has received funding from Industry (GlaxoSmithKline) for investigator-led research. She does not receive any personal payments from Industry. All other authors have no conflicts to declare. They declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Standardizing case definitions for priority vaccine safety conditions facilitates uniform evaluation and consolidation of data obtained from different settings. The Brighton Collaboration case definitions (BCCD) were created to support this harmonization and enable classification from level 1 (most certain) to level 5 (not a case) of certainty. Assessing the performance of BCCD in practice is critical, particularly in resource-limited settings, where many new vaccines may be introduced without prior monitoring in high-income countries. We assessed the performance of BCCD in Addis Ababa, Ethiopia, as applicable to COVID-19 and other vaccines., Methods: Active surveillance was conducted at Tikur Anbessa Specialized Hospital, the largest referral hospital in Ethiopia. During June 1, 2022-May 31, 2023, three trained physicians prospectively identified patients eligible for COVID-19 vaccination (regardless of vaccine receipt) who presented with one or more of eleven pre-specified adverse events of special interest (AESI) from the emergency department and inpatient wards. Standardized data collection forms were used to capture patient information and assign level of certainty (LOC), regardless of vaccination status for COVID-19. We conducted descriptive analysis to characterize cases and the LOCs reached for each AESI., Results: We detected 203 AESI cases. The most detected conditions were thrombosis and thromboembolism (n = 100, 49 %) and generalized convulsions (n = 38, 19 %). Ninety-six percent of the cases were confirmed at levels 1-3 (n = 187) or level 5 (n = 9) LOC. Non-classifiable (level 4) cases were observed for pericarditis (n = 2), encephalitis (n = 2), myelitis (n = 2), and generalized convulsion (n = 1)., Conclusion: The BCCD were successfully applied in > 95 % of cases in a large referral hospital in Ethiopia, with generalized convulsion, pericarditis, and encephalomyelitis as the exceptions. We recommend further evaluation in other low-resource settings, particularly in rural or non-referral hospitals, to gain additional insights into performance of these definitions for revision or adaptation, as needed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Introduction: In 2016, the Kenya National Immunization Technical Advisory Group requested additional programmatic and cost effectiveness data to inform the choice of strategy for a national influenza vaccination program among children aged 6-23 months of age. In response, we conducted an influenza vaccine demonstration project to compare the performance of a year-round versus campaign-mode vaccination strategy. Findings from this demonstration project will help identify essential learning lessons for a national program., Methods: We compared two vaccine delivery strategies: (i) a year-round vaccination strategy where influenza vaccines were administered throughout the year at health facilities. This strategy was implemented in Njoro sub-county in Nakuru (November 2019 to October 2021) and Jomvu sub-county in Mombasa (December 2019 to October 2021), (ii) a campaign-mode vaccination strategy where vaccines were available at health facilities over four months. This strategy was implemented in Nakuru North sub-county in Nakuru (June to September 2021) and Likoni sub-county in Mombasa (July to October 2021). We assessed differences in coverage, dropout rates, vaccine wastage, and operational needs., Results: We observed similar performance between strategies in coverage of the first dose of influenza vaccine (year-round strategy 59.7 %, campaign strategy 63.2 %). The coverage obtained in the year-round sub-counties was similar (Njoro 57.4 %; Jomvu 63.1 %); however, more marked differences between campaign sub-counties were observed (Nakuru North 73.4 %; Likoni 55.2 %). The campaign-mode strategy exceeded the cold chain capacity of participating health facilities, requiring thrice monthly instead of once monthly deliveries, and was associated with a two-fold increase in workload compared to the year-round strategy (168 vaccines administered per day in the campaign strategy versus 83 vaccines administered per day in the year-round strategy)., Conclusion: Although both strategies had similar coverage levels, the campaign-mode strategy was associated with considerable operational needs that could significantly impact the immunization program., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: SSC has since left the US CDC and is currently an employee of Sanofi Vaccines, Lyon, France., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Estimating the burden of disease averted by vaccination can assist policymakers to implement, adjust, and communicate the value of vaccination programs. Demonstrating the use of a newly available modeling tool, we estimated the burden of influenza illnesses averted by seasonal influenza vaccination in El Salvador, Panama, and Peru during 2011-2018 among two influenza vaccine target populations: children aged 6-23 months and pregnant women., Methods: We derived model inputs, including incidence, vaccine coverage, vaccine effectiveness, and multipliers from publicly available country-level influenza surveillance data and cohort studies. We also estimated changes in illnesses averted when countries' vaccine coverage was achieved using four different vaccine deployment strategies., Results: Among children aged 6-23 months, influenza vaccination averted an estimated cumulative 2,161 hospitalizations, 81,907 medically-attended illnesses, and 126,987 overall illnesses during the study period, with a prevented fraction ranging from 0.3 % to 12.5 %. Among pregnant women, influenza vaccination averted an estimated cumulative 173 hospitalizations, 6,122 medically attended illnesses, and 16,412 overall illnesses, with a prevented fraction ranging from 0.2 % to 10.9 %. Compared to an influenza vaccine campaign with equal vaccine distribution during March-June, scenarios in which total cumulative coverage was achieved in March and April consistently resulted in the greatest increase in averted illness (23 %-3,129 % increase among young children and 22 %-3,260 % increase among pregnant women)., Discussion: Influenza vaccination campaigns in El Salvador, Panama, and Peru conducted between 2011 and 2018 prevented hundreds to thousands of influenza-associated hospitalizations and illnesses in young children and pregnant women. Existing vaccination programs could prevent additional illnesses, using the same number of vaccines, by achieving the highest possible coverage within the first two months of an influenza vaccine campaign., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: In early 2021, the 10-valent Pneumococcal conjugate vaccine (PCV10) was replaced with 13-valent (PCV13) by the federal directorate of immunization (FDI), Pakistan. We assessed the impact of a higher valent vaccine, PCV13, on the serotype distribution of nasopharyngeal carriage in rural Pakistan., Methods: Children <2 years were randomly selected from two rural union councils of Matiari, Sindh in Pakistan between September-October,2022. Clinical, sociodemographic and vaccination histories were recorded. Nasopharyngeal swabs were collected and processed at Infectious Disease Research Laboratory, Aga Khan University, Karachi. Whole genome sequencing was performed on the culture positive isolates., Results: Of the 200 children enrolled, pneumococcus was detected in 140(70 %) isolates. Majority of age-eligible children (60.1 %,110/183) received 3 PCV13 doses. PCV10 carriage declined from 13.2 %(78/590) in 2017/18 to 7.2 % (10/140) in 2022, additional PCV13 serotypes (3, 6A/6C and 19A) decreased from 18.5 %(109/590) to 11.4 %(16/140) while non-PCV13 serotypes increased from 68.3 %(403/590) to 81.4 %(114/140). There were 88.5 %(n = 124), 80.7 %(n = 113), 55.0 %(n = 77), and 46.0 %(n = 65) isolates predicted to be resistant to cotrimoxazole, penicillin(meningitis cut-off), tetracycline, and erythromycin respectively., Conclusion: Replacing PCV10 with PCV13 rapidly decreased prevalence of PCV13 carriage among vaccinated children in Matiari, Pakistan. Vaccine-driven selection pressure may have been responsible for the increase of non-PCV13 serotypes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: The 13-valent pneumococcal conjugate vaccine (PCV13) has been recommended for infants in Argentina's national immunization program (NIP) in a 2 + 1 schedule since 2012. Licensure of the 15-valent vaccine (PCV15) is anticipated soon, and the 20-valent vaccine (PCV20) recently received regulatory approval. This cost-effectiveness analysis examined the public health and economic implications of transitioning from PCV13 to either PCV15 or PCV20 in Argentina's pediatric NIP., Methods: A decision-analytic Markov model was used with a 10-year time horizon and a 3.0% annual discount rate for costs and benefits. Vaccine effectiveness estimates were derived from Argentinian surveillance data, PCV13 clinical effectiveness and impact studies, and PCV7 efficacy studies. Population, epidemiologic, and economic inputs were obtained from literature and Argentinian-specific data. The study adopted a healthcare system perspective; sensitivity and scenario analyses were conducted to assess input parameters and structural uncertainty., Results: Compared with PCV13, PCV20 was estimated to avert an additional 7,378, 42,884, and 172,389 cases of invasive pneumococcal disease (IPD), all-cause pneumonia, and all-cause otitis media (OM), respectively, as well as 3,308 deaths, resulting in savings of United States Dollars (USD) 50,973,962 in direct medical costs. Compared with PCV15, PCV20 was also estimated to have greater benefit, averting an additional 6,140, 35,258, and 142,366 cases of IPD, pneumonia, and OM, respectively, as well as 2,624 deaths, resulting in savings of USD 37,697,868 in direct medical costs. PCV20 was associated with a higher quality-adjusted life year gain and a lower cost (i.e., dominance) versus both PCV13 and PCV15. Results remained robust in sensitivity analyses and scenario assessments., Conclusion: Over a 10-year horizon, vaccination with PCV20 was expected to be the dominant, cost-saving strategy versus PCV13 and PCV15 in children in Argentina. Policymakers should consider the PCV20 vaccination strategy to achieve the greatest clinical and economic benefit compared with lower-valent options., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Lucila Rey-Ares reports a relationship with Pfizer Inc that includes: employment. An Ta reports a relationship with Cytel Inc that includes: employment. An Ta reports a relationship with Pfizer Inc that includes: consulting or advisory. Donata Freigofaite reports a relationship with Cytel Inc that includes: employment. Sophie Warren reports a relationship with Pfizer Inc that includes: employment. Mercedes Mac Mullen reports a relationship with Pfizer Inc that includes: employment. Carolina Carballo reports a relationship with Pfizer Inc that includes: employment. Liping Huang reports a relationship with Pfizer Inc that includes: employment. The authors declare the following financial interests/personal relationships, which may be considered as potential competing interests: LRA, CC, and LH are employees of Pfizer Inc. SW and MM were employed by Pfizer Inc. at the time of manuscript development. AT received consulting fees from Pfizer Inc. for the study and manuscript development and is an employee of Cytel Inc. DF was employed by Cytel Inc. at the time of manuscript development. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

In the context of polio eradication efforts, accurate assessment of vaccination programme effectiveness is essential to public health planning and decision making. Such assessments are often based on zero-dose children, estimated using the number of children who did not receive the first dose of the Diphtheria-Tetanus-Pertussis containing vaccine as a proxy. Our study introduces a novel approach to directly estimate the number of children susceptible to poliovirus type 2 (PV2) and uses this approach to provide district-level estimates for South Africa of susceptible children born between 2017 and 2022. We used district-level data on annual doses of inactivated poliovirus vaccine (IPV) administered, live births, and population sizes, from 2017 through 2022. We imputed missing vaccination data, implemented flexible assumptions regarding dose distribution in the eligible population, and used estimated efficacy values for one, two, three, and four doses of IPV, to compute the number of susceptible and immune children by birth year. We validated our approach by comparing an intermediary output with zero-dose children (ZDC) estimated using data reported by WHO/UNICEF Estimates of National Immunization Coverage (WUENIC). Our results indicate high heterogeneity in susceptibility to PV2 across South Africa's 52 districts as of the end of 2022. In children under 5 years, PV2 susceptibility ranged from approximately 30 % in districts including Xhariep (31.9 %), Ekurhuleni (30.1 %), and Central Karoo (29.8 %), to less than 4 % in Sarah Baartman (1.9 %), Buffalo City (2.1 %), and eThekwini (3.2 %). Our susceptibility estimates were consistently higher than ZDC over the timeframe. We estimated that ZDC decreased nationally from 155,168 (152,737-158,523) in 2017 to 108,593 in 2021, and increased to 127,102 in 2022, a trend consistent with ZDC derived from data reported by WUENIC. While our approach provides a more comprehensive profile of PV2 susceptibility, our susceptibility and ZDC estimates generally agree in the ranking of districts according to risk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Recently, the first RSV vaccines have been approved, but vaccine hesitancy still poses great challenges to immunization programs., Objective: To investigate this phenomenon in the context of the new RSV vaccines and an increased virus activity in 2022/23, we assessed parental knowledge and attitudes towards general childhood and RSV vaccines., Methods: Parents of infants from 0-36 months completed an online questionnaire on demographics, socio-economic status, mental well-being, knowledge on RSV and perceptions of disease, attitudes to general childhood and RSV vaccines. The survey was conducted from February-June 2023 in the region of Regensburg, Germany. We compared continuous or categorical data with two-sided t-tests or Chi-square tests, respectively. Linear and logistic regression models were used to adjust for confounders., Results: From 191 survey participants, 84 % had never refused any recommended vaccination and 91 % trusted their paediatrician's information. 11 % felt that children should have fewer vaccinations or rather get over the illness. Parents who were supportive or undecided about RSV vaccination were less likely to be vaccine hesitant in general (OR 0.03, p < 0.001; OR 0.13, p = 0.003). 58 % reported to have basic or good knowledge on RSV, correlating with a higher socioeconomic index (p = 0.049). 24 % were undecided about RSV immunization, while all parents rated its benefit high in the child's first year of life. Parents who refused RSV vaccination were less concerned about the infection compared to vaccine supporters (OR 0.44, p < 0.001). Parents with previously hospitalized (OR 3.88, p = 0.017) or preterm born children (OR 5.12, p = 0.026) were generally more concerned., Conclusion: Many factors influence parental decision-making leading to three main groups of attitudes: vaccine acceptors, refusers and hesitant but accessible parents. They (24%) represent the "target group" to increase vaccine uptake. Information on the vaccine-preventable disease reduces vaccine hesitancy, underlining the importance of healthcare professionals who remain an important source of trust., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Isolation of cases and quarantining of non-immune contacts are the mainstay of measles outbreak management in elimination settings. Serology testing of exposed contacts may not be feasible in large outbreaks; therefore, vaccination history is used as a proxy for determining immunity to measles and thus prevention of onward virus transmission. This study sought to investigate the risk of measles virus transmission from individuals with a history of one or two doses of measles-containing vaccine (MCV)., Methods:  Retrospective analysis of data from measles cases reported to Auckland Regional Public Health Service during the 2019 Auckland region measles outbreak. Vaccination history was verified using patient records and the New Zealand National Immunisation Register. Onward transmission was determined through case interviews and assessment of exposed contacts., Results:  1451 measles cases were assessed as eligible for vaccination at the time of measles outbreak. Of these, 1015 (70.0%) were unvaccinated, 220 (15.2%) had unknown vaccination status, 139 (9.6%) had received only one dose of MCV and 77 (5.3%) had received two doses of the vaccine. Compared to unvaccinated cases, the odds of onward transmission were lower among those with one dose only (OR 0.41, 95% CI: 0.20-0.75) or two doses of MCV (OR 0.44, 95% CI: 0.17-0.95). Median time since vaccination was longer among those with onward transmission compared to those without onward transmission for one and two doses of the vaccine, suggesting a potential effect of waning immunity among this cohort., Conclusion:  These findings support the hypothesis that measles cases with a history of prior vaccination are less likely to transmit the virus to others compared to unvaccinated cases. Such information can be used to support decisions around quarantine requirements for vaccinated contacts in future measles outbreaks., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. All authors attest they meet the ICMJE criteria for authorship., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Meningococcal disease control in the UK relies on various vaccines, with the discontinuation of the Hib/MenC combination vaccine Menitorix® in 2018 necessitating reassessment of the immunisation strategy. The quadrivalent MenACWY vaccine emerges as a promising long-term solution, already integrated into the teenage immunisation regimen. While indirect control of group W and C cases is anticipated through existing programs, the high incidence of meningococcal disease in infancy underscores the potential benefits of infant/toddler vaccination., Methods: Utilizing data from two UK studies, we recalibrated age-specific carriage prevalence curves and estimated the proportion of meningococcal carriage attributed to ACWY and non-ACWY strains. Employing a dynamic transmission model, we evaluated the combined indirect effects of the teenage MenACWY vaccination initiative and the direct impact of administering MenACWY vaccine at either 3 or 12 months, alongside ongoing 4CMenB vaccination efforts. Given the pandemic-induced decline in cases and alterations in social contact patterns reported in prior research, we also simulated the transmission model to reflect periods of COVID-19 lockdown., Results: Our projections indicate effective control of carriage and disease associated with groups A, C, W, and Y through the teenage vaccination campaign. Assuming sustained high uptake of teenage vaccines amid pandemic scenario, we forecast MenACWY carriage prevalence to be below 1% by 2025. Across all scenarios, the impact of an infant/toddler MenACWY program on case reduction remains modest. Notably, administering the MenACWY dose at 3 months yields a greater number of prevented cases compared to administration at 12 months. With sustained uptake of teenage vaccination, our estimates suggest that between 3 and 22 cases could be averted in a 2025 birth cohort through a 3-month MenACWY dose., Conclusions: Provided teenage uptake remains high and the infant 4CMenB programme is maintained, we suggest that few cases will be prevented from an infant/ toddler MenACWY dose., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: New interventions are available for the prevention of respiratory syncytial virus (RSV) disease in young infants. We aimed to assess the potential impact and cost-effectiveness of using a long-acting monoclonal antibody (RSV mAb) or maternal RSV vaccine in the Argentine context., Methods: We used a static proportionate outcomes model to calculate the costs and consequences of using RSV mAb or maternal RSV vaccine over a ten-year period (2025-2034) in Argentina, assuming both year-round and seasonal administration. We compared each intervention to no pharmaceutical RSV intervention. The primary outcome was the discounted cost per disability-adjusted life year (DALY) averted from a societal perspective. We assumed willingness-to-pay of US$ 12,285 per DALY averted (0.9 times the national gross domestic product per capita). We used population study data on costs and disease burden and the efficacy of clinical trials of both interventions as inputs. We ran deterministic and probabilistic uncertainty analyses., Findings: Either strategy (RSV mAb or maternal RSV vaccine) could prevent >25% of RSV deaths aged <5 years and ∼30% aged <6 months (the age group where most intervention impact occurs). With a dose price of $US 50, both products have a 100% probability of being cost-effective compared to no intervention (US$ 5283 [95%CI $5203-$5363] and US$ 5522 [95%CI $5427 - $5617] per DALY averted for year-round use of RSV mAb and maternal RSV vaccine, respectively). Similar health impact could be achieved by a six-month seasonal strategy, which could improve cost-effectiveness by around 45% (assuming the dose price is unchanged)., Interpretation: Either RSV mAb or maternal RSV vaccine are worth consideration in Argentina when priced at ≤US$ 50 per dose. A seasonal strategy could improve cost-effectiveness., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mauricio Caballero reports financial support was provided by Bill & Melinda Gates Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Routine childhood immunization is one of the most effective methods of preventing infectious diseases in children. In Argentina, there has been a decline in routine immunization coverage since 2015, with very little evidence to date on underlying drivers of this steady decline. We administered an online nationwide behavioral insights survey in Argentina between July 1-25, 2022, targeting parents with at least one child under the age of 12 years. Our survey included 1504 parents, 7% (n = 111) of whom did not or only partially vaccinated their children. We found that, compared to the youngest parents (aged 18-24), older parents were less likely to under-vaccinate their children (e.g., 30-34 year-old parents: adjusted Odds Ratio (aOR): 0.31, 95% Confidence Interval (CI) 0.16-0.57). Parents who undervaccinated their children were more likely to take vaccination advice from parent and wellness social media influencers (parent influencers: aOR 2.51, 95% CI 1.46-4.31), and were less likely to trust the social media accounts of official health organizations (aOR 0.82, 95% CI 0.70-0.96). Furthermore, these parents had heightened concerns about routine immunizations, including the number of vaccines given to children and potential for adverse side effects. When asked whether they knew enough to make a vaccine decision for their children, parents who undervaccinated their children were more likely to report that they did not know enough about vaccines or the vaccination schedule to make a decision. These results offer important insights into parental concerns surrounding routine childhood immunization and suggest potential drivers of - and solutions to - the decline in routine immunization seen in Argentina since 2015., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Saad B Omer reports financial support was provided by UNICEF. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The annual administration of the influenza vaccine is the most effective method for preventing influenza. We have evaluated the effectiveness of the inactivated influenza vaccine in children aged 6 months to 15 years across the seasons from 2013/2014 to 2022/2023. This study aims to investigate the effectiveness of the inactivated influenza vaccine in the 2023/2024 season, the first year following the easing of strict COVID-19 measures, and possibly the last season when only the inactivated vaccine is available on the market., Methods: Adjusted vaccine effectiveness for the 2023/2024 season was assessed using a test-negative case-control design, with results based on polymerase chain reaction and rapid influenza diagnostic tests. Vaccine effectiveness was calculated by influenza type and patient hospitalization/outpatient status., Results: A total of 1832 children were recruited. The inactivated influenza vaccine was effective in preventing both symptomatic influenza A and B in both inpatient and outpatient settings. Overall vaccine effectiveness for influenza A was 51% (95% confidence interval [CI], 23%-69%, n = 930) in inpatient settings and 54% (95%CI, 27%-71%, n = 559) in outpatient settings. For influenza B, effectiveness was 60% (95%CI, 22%-79%, n = 859) in inpatient settings and 56% (95%CI, 26%-74%, n = 558) in outpatient settings. Analysis suggested that administering two doses enhanced effectiveness specifically against influenza B., Conclusions: This is the first study to demonstrate influenza vaccine effectiveness in children after the relaxation of strict COVID-19 measures in Japan (2023/2024). We recommend the current inactivated vaccine for preventing both influenza A and B in children, with consideration for the potential use of two doses to enhance effectiveness against influenza B., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Masayoshi Shinjoh (Shinjo) reports a relationship with MSD KK that includes: speaking and lecture fees. Masayoshi Shinjoh (Shinjo) reports a relationship with Meiji Seika Pharma Co Ltd. that includes: speaking and lecture fees. Masayoshi Shinjoh (Shinjo) reports a relationship with Mitsubishi Tanabe Pharma Corporation that includes: speaking and lecture fees. Masayoshi Shinjoh (Shinjo) reports a relationship with KM Biologics Co Ltd. that includes: speaking and lecture fees. Masayoshi Shinjoh (Shinjo) reports a relationship with Shionogi and Co Ltd. that includes: speaking and lecture fees. Masayoshi Shinjoh (Shinjo) reports a relationship with DAIICHI SANKYO COMPANY, LIMITED that includes: speaking and lecture fees. Masayoshi Shinjoh (Shinjo) reports a relationship with Takeda Pharmaceutical Company Limited that includes: consulting or advisory and speaking and lecture fees. Masayoshi Shinjoh (Shinjo) reports a relationship with Pfizer Japan Inc. that includes: consulting or advisory. Masayoshi Shinjoh (Shinjo) reports a relationship with Janssen Pharmaceutical KK that includes: consulting or advisory. Masayoshi Shinjoh (Shinjo) reports a relationship with Astellas Pharma Inc. that includes: consulting or advisory. This work was supported by JSPS KAKENHI, Japan (Grant Number JP20K10546). Outside this study, the corresponding author received Health Labour Sciences Research Grant, Japan (2024). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)