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Background: In recent years, notified pertussis cases have been increasingly documented in China. It raised a new public health concern of potential optimization in immunization strategy. This study was aimed to determine the cost-effectiveness of different immunization strategies against pertussis-containing vaccines for 6-year-old pre-school children in Shanghai., Methods: A Markov-decision tree model was applied to evaluate two pertussis immunization strategies for 6-year-old pre-school children as following: (1) 1 dose of acellular pertussis (aP) contained vaccine (DTaP or Tdap) booster vaccinated at 6 years of age, and (2) no booster at 6 years of age regimen. Primary outcomes included quality-adjusted life years (QALYs), costs, and incremental cost-utility ratios (ICUR). Sensitivity analyses were performed. The analysis was conducted over a study period of 14 years from a societal perspective., Results: Compared to no booster immunization strategy, administering 1 dose of acellular pertussis (aP) contained vaccine (DTaP or Tdap) booster at 6 years of age, resulted in an average cost reduction of CNY 814.16 (USD 116) per individual, an increase in QALYs by 0.00066, and a rise in per capita net monetary benefit (NMB) by CNY 933.51 (USD 132). The total costs over the study period were reduced by CNY 160.59 million (USD 23 million), utility increased by 130.49 QALYs, and NMB increased by CNY 184.14 million (USD 26 million)., Conclusions: Implementing acellular pertussis booster immunization for 6-year-old pre-school children in Shanghai emerges as a cost-saving immunization strategy, with both cost savings and utility gains., 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: Respiratory syncytial virus (RSV) fusion protein stabilized in the prefusion conformation (RSVPreF3) was under investigation as a maternal vaccine., Methods: This phase 2, randomized, placebo-controlled, single-dose, multicenter study enrolled healthy, nonpregnant women, randomized 1:1:1:1:1 to 5 parallel groups studying RSVPreF3 (60 or 120 µg) coadministered with diphtheria, tetanus, and acellular pertussis vaccine (dTpa) or placebo, and dTpa coadministered with placebo. Safety and humoral immune responses were assessed. An extension phase also assessed a RSVPreF3 120 μg vaccination 12-18 months after first vaccination., Results: The safety profile of RSVPreF3 was unaffected by dose or dTpa coadministration. Solicited and unsolicited adverse events (AEs) were evenly distributed across study groups. Injection-site pain was higher following the second vaccination versus the first vaccination. Medically attended AEs were rare (<5% overall). Both RSVPreF3 dose levels (alone and with dTpa) were immunogenic, increasing levels of RSV-A neutralizing antibody ≥8-fold and anti-RSVPreF3 IgG antibody ≥11-fold at 1 month postvaccination, which persisted at 12-18 months postvaccination; modest 2-fold increases were observed with a second RSVPreF3 vaccination., Conclusions: This study indicates RSVPreF3 coadministration with dTpa induces robust immune responses and is well tolerated, regardless of the RSVPreF3 dose level used., Clinical Trials Registration: NCT04138056., Competing Interests: Potential conflicts of interest. N. He., D. Y., N. Hu., P. v. d. S., I. L., and J. H. K. are GSK employees. P. v. d. S., B. A., I. L., and J. H. K. receive GSK shares/stock options as part of their employee remuneration. M. F. received a salary as principal investigator for the Colchester Research Group which he co-owns with his wife, Dr Linda Ferguson, and which took part in this study. I. L.-R. received fees from GSK for conducting the present work; their institution has received grants from Virometix and Icosavax; and has received personal fees from Janssen for participating in an Advisory Board. S. P. has no potential conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Vaccination rates for mumps, measles, and rubella (MMR) and tetanus, diphtheria, pertussis, and polio (Tdap-IPV) fall short of global targets, highlighting the need for vaccination interventions. This study examines the effectiveness of a city-wide school-based educational vaccination intervention as part of an on-site vaccination program aimed at increasing MMR and Tdap-IPV vaccination rates versus on-site vaccination alone among sociodemographically diverse students from Berlin, Germany. The study was a 1:1 two-arm cluster randomized controlled trial, with schools randomly assigned to either the Educational Class Condition (ECC) or the Low-Intensity Information Condition (LIIC). Both received an on-site vaccination program, while students in the ECC received an additional educational unit. Primary outcomes were MMR and Tdap-IPV vaccination rates. In total, 6512 students from 25 randomly selected urban area secondary schools participated. For students providing their vaccination documents on the day of the intervention (2273, 34.9%), adjusted Poisson mixed models revealed significant between-group differences in favor of the ECC (MMR: logRR = 0.47, 95%CI [0.01,0.92], RR = 1.59; Tdap-IPV: logRR = 0.28, 95%CI [0.10,0.47], RR = 1.32). When adjusting for socioeconomic and migration background, between-group differences became non-significant for MMR but remained significant for Tdap-IPV. Findings suggest that educational, school-based on-site vaccination appears to be a promising strategy for increasing vaccination uptake in adolescents., (© 2024 The Authors. Applied Psychology: Health and Well‐Being published by John Wiley & Sons Ltd on behalf of International Association of Applied Psychology.)

Background: Hispanic infants bear the burden of pertussis infection. We examined pertussis protection from vaccination in infants with US-born and foreign-born Hispanic mothers., Methods: Retrospective cohort study of infants up to 1 year of age. Secondary data of mothers with continuous membership since the 27th week of pregnancy with infants born 1/1/2012-12/31/2017 in an integrated health care delivery organization, which broadly represent the Southern California population., Results: Foreign-born Hispanic mothers had higher prenatal tetanus, diphtheria, acellular pertussis (Tdap) uptake compared to US-born white mothers [adjusted risk ratio (aRR): 1.04, 95% confidence interval (CI): 1.03, 1.05]. Infants with mothers on Medicaid insurance disproportionately did not enroll in the health plan by the time they were eligible for their first dose of the DTaP vaccine (68.4%). Once initiating the infant vaccine series, foreign-born Hispanic mothers more likely adhered than US-born white mothers (aRR: 1.05, CI: 1.02, 1.08)., Discussion: In an integrated health system, disparities in vaccine uptake can be minimized. Infants who are born to mothers with Medicaid insurance and are not enrolled in the health plan after birth may be under-protected from pertussis., (© 2023. W. Montague Cobb-NMA Health Institute.)

Importance: Maternal tetanus, diphtheria, and acellular pertussis (Tdap) vaccination protects newborns against severe pertussis. Data on transplacental antibody transfer on Tdap vaccination before 24 weeks' gestation remain scarce and are particularly relevant for preterm infants to increase the time interval for maternal antibody transfer., Objective: To assess noninferiority of anti-pertussis toxin (anti-PT) immunoglobulin G (IgG) antibody levels at age 2 months in early- to late-term infants following Tdap vaccination between 20 0/7 and 24 0/7 weeks' gestation compared with 30 0/7 and 33 0/7 weeks' gestation and compared with preterm infants., Design, Setting, and Participants: This prospective, multicenter cohort study included pregnant women aged 18 years or older in birthing centers and hospitals in the Netherlands between August 2019 and November 2021 who received Tdap vaccination between 20 0/7 and 24 0/7 weeks' gestation. Women with imminent premature birth were recruited if they had received maternal Tdap vaccination between 20 and 24 weeks' gestation. Blood samples were collected from mothers at delivery, from the umbilical cord, and from infants at age 2 months. Data from infants' blood samples at age 2 months were compared with a reference cohort (recruited between January 2014 and February 2016) of early- to late-term infants of the same age whose mothers had received Tdap vaccination between 30 0/7 and 33 0/7 weeks' gestation., Exposure: Maternal Tdap vaccination between 20 0/7 and 24 0/7 weeks' gestation or 30 0/7 and 33 0/7 weeks' gestation., Main Outcomes and Measures: The primary outcome was the geometric mean concentration (GMC) of anti-PT IgG antibodies in early- to late-term infants (≥37 0/7 weeks' gestation) at age 2 months, comparing maternal Tdap vaccination between 20 0/7 and 24 0/7 weeks' vs 30 0/7 and 33 0/7 weeks' gestation (reference cohort). Anti-PT GMC in 2-month-old infants born preterm (<35 0/7 weeks' gestation) compared with early- to late-term infants after maternal Tdap vaccination between 20 and 24 weeks' gestation was a secondary outcome., Results: In total, 221 women who delivered 239 offspring were enrolled in the study; 66 early- to late-term infants (median gestational age [GA], 40.6 weeks [IQR, 39.8-41.0 weeks]; 38 [57.6%] male) and 73 preterm infants (median GA, 32.1 weeks [IQR, 29.5-33.0 weeks]; 42 [54.5%] female) had blood samples collected at 2 months of age. Anti-PT GMC was 14.7 IU/mL (95% CI, 10.6-20.4 IU/mL) in early- to late-term infants following maternal Tdap vaccination between 20 0/7 and 24 0/7 weeks' gestation compared with 27.3 IU/mL (95% CI, 20.1-37.1 IU/mL) in 55 infants in the reference group (median GA, 40.3 [IQR, 39.1-41.0]; 33 [60.0%] female). The mean anti-PT GMC in preterm infants in the study group was 11.2 IU/mL (95% CI, 8.1-15.3 IU/mL) (P = .23 compared with early- to late-term infants)., Conclusions and Relevance: In this cohort study, 2-month-old preterm and early- to late-term infants showed significantly lower anti-PT antibody levels following maternal Tdap vaccination between 20 0/7 and 24 0/7 weeks' gestation compared with 30 0/7 and 33 0/7 weeks' gestation; preterm and early- to late-term infants had similar anti-PT antibody levels, but both groups showed significantly lower antibody levels compared with the reference group. Epidemiological research should investigate whether maternal Tdap vaccination before 24 weeks' gestation provides sufficient protection against clinical pertussis, particularly in preterm infants, as long as no correlate of protection is available.

Aim/objective: This study investigates placental antibody transfer following recombinant pertussis vaccination in pregnancy in a real-world setting., Methods: This postmarketing observational study recruited pregnant women vaccinated with monovalent recombinant acellular pertussis (aP) vaccine (aP gen ; n = 199) or combined to tetanus-diphtheria (TdaP gen ; n = 200), or Td-vaccine only (n = 54). Pregnancy, delivery, and neonatal outcomes were assessed. Cord blood was collected postdelivery and pertussis toxin (PT)-IgG, filamentous hemagglutinin (FHA)-IgG, and PT-neutralizing antibodies (PT-Nab) were assessed., Results: No adverse pregnancy, delivery, or neonatal outcomes attributed to aP gen , TdaP gen , or Td vaccination were reported. High anti-PT antibody levels were detected in cord samples from women vaccinated with aP gen (geometric mean concentration [GMC] PT-IgG 206.1 IU/ml, 95% confidence intervals [CI]: 164.3-258.6; geometric mean titer [GMT] PT-Nab 105.3 IU/ml, 95% CI: 81.7-135.8) or TdaP gen (GMC PT-IgG 153.1 IU/ml, 95% CI: 129.1-181.5; GMT PT-Nab 81.5 IU/ml, 95% CI: 66.4-100.0). In the Td-only group, anti-PT antibodies were low (GMC PT-IgG 6.5 IU/ml, 95% CI: 4.9-8.8; GMT PT-Nab 3.8 IU/ml, 95% CI: 2.8-5.1). The same was found for FHA-IgG. Recombinant pertussis vaccination at <27 or 27-36 weeks gestation induced similar cord pertussis antibody levels., Conclusion: This first real-world study confirms that recombinant pertussis vaccination in the second or third trimester of pregnancy results in high levels of passive immunity in infants. Thai Clinical Trial Registry: TCTR20200528006., Competing Interests: Declarations of competing interest HTP, SM, WW, IKP, LF, CK, and VY are employed by BioNet. All other authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Despite high pediatric vaccination coverage rates (VCRs), pertussis incidence has increased worldwide, including in several countries in Latin America in the last two decades. Given the few vaccine effectiveness (VE) studies in Latin American countries, this retrospective, observational, cohort study estimated the effectiveness of hexavalent acellular (aP) primary and booster vaccination (wP) against pertussis in infants (6.5-18.5 months) and children (18.5-48.5 and 48.5-72.5 months) in Panama. Age-specific incidence rates (IRs) were calculated for the vaccine's pre-initiation (2001-2013), initiation (2014), and post-initiation (2015-2019) periods. VCRs and trends were determined, and VE was analyzed using a case coverage or screening method to compare proportions of vaccinated cases and vaccinated individuals in the population. Between 2001-2019, 868 confirmed pertussis cases were reported in Panama; 712 (82.0%; 54.8 cases/year) during the pre-initiation period, 19 (2.2%; 19 cases/year) during the initiation period, and 137 (15.8%; 27.4 cases/year) during the post-initiation period. Panama underwent cyclical increases in IRs, which varied between age groups. VCRs increased for primary and booster doses. Between 2015 and 2019, third-dose yearly vaccine coverage increased, on average, 3.3%. Specifically, during the post-initiation period, 109/137 (79.6%) of cases were unvaccinated. Relative VE was estimated at 96.2% [95% CI: 86.5%, 98.9%] with three doses; 100% with 4 and 5 booster doses. Absolute VE was estimated at 99.3% with three doses only. These results show that vaccination played an important role in maintaining a low number of pertussis cases in Panama, affirming the need for sustained investment and commitment to vaccination programs.

Influenza, COVID-19, tetanus, pertussis and hepatitis B pose increased risk for pregnant women and infants and could be mitigated by maternal immunization. In India Tetanus-diphtheria (Td) and COVID-19 vaccines are recommended during pregnancy, while influenza and tetanus-acellular pertussis-diphtheria (Tdap) vaccines are not. We conducted a multicenter study from November 2021 to June 2022 among pregnant women ( n  = 172) attending antenatal clinics in three public hospitals in West Bengal, to understand the factors that influence women's decisions to get vaccinated during pregnancy. Questions assessed vaccination coverage, knowledge, intention and willingness to pay for influenza vaccine, and factors influencing decisions to get Td, influenza, and COVID-19 vaccines. 152/172 (88.4%) women were vaccinated with Td, 159/172 (93%) with COVID-19, 1/172 (0.6%) with influenza, and none with Tdap. 10/168 (6%) had received hepatitis B vaccine (HBV). Community health workers advice was crucial for Td uptake and, the belief of protection from COVID for COVID-19 vaccines. Most women were unaware about Tdap (96%), influenza (75%), and influenza severity during pregnancy and infancy (85%). None were advised for influenza vaccination by healthcare providers (HCP), albeit, 93% expressed willingness to take, and pay INR 100-300 (95% CI: ≤100 to 300-500) [$ 1.3-4.0 (95% CI: ≤1.3, 4-6.7)] for it. Vaccination on flexible dates and time, HCP's recommendation, proximity to vaccination center, and husband's support were most important for their vaccination decisions. Women were generally vaccine acceptors and had high uptake of vaccines included in the Universal Immunization Program (UIP). Inclusion of influenza, Tdap, and HBV into UIP may improve maternal vaccine uptake.

A panel of 24 international experts met in July 2022 to discuss challenges associated with pertussis detection, monitoring, and vaccination in adults; conclusions from this meeting are presented. There has been a shift in the epidemiology of pertussis toward older children and adults. This shift has been attributed to the waning of infection- or vaccine-induced immunity, newer detection techniques causing detection bias, and possibly the replacement of whole-cell pertussis with acellular vaccines in high-income countries, which may lead to immunity waning more quickly. The burden of adult pertussis is still likely under-ascertained due to widespread under-recognition by healthcare professionals (HCPs), under-diagnosis, and under-reporting in this age group. Non-standardized testing guidance and varied case definitions have contributed to under-reporting. Key barriers to HCP engagement with the tetanus, diphtheria, and pertussis (Tdap) vaccine include low awareness, lack of time/funding, and lack of motivation due to low prioritization of Tdap.

To fully understand the safety of DTaP-IPV/Hib vaccination, we evaluated the differences between DTaP-IPV/Hib co-administration and separate administration of the DTaP, IPV and Hib vaccines (DTaP+IPV+Hib) based on adverse events following immunization (AEFI). All AEFI reported in Hebei Province, China, between 2020 and 2022 were included in this study. The risk difference (RD%), relative risk (RR), and Chi-square value were used to compare the differences in reported rates of AEFI between the DTaP-IPV/Hib and DTaP+IPV+Hib groups. From 2020 to 2022, 130 AEFI cases were reported in Hebei Province after DTaP-IPV/Hib vaccination, corresponding to an AEFI reported rate of 66.9/million doses, which was significantly lower than that for DTaP+IPV+Hib (9836 AEFI with a reported rate of 637.8/million doses). The overall reported rate of non-severe AEFI for DTaP+IPV+Hib vaccines was 9.5 times that of DTaP-IPV/Hib vaccination [ 95% confidence interval ( CI) : 8.0, 11.3]. Meanwhile, the reported rate of AEFI among infants aged 0-1 y was 9.8 times higher for DTaP+IPV+Hib than for DTaP-IPV/Hib ( 95% CI : 8.2, 11.7). DTaP+IPV+Hib vaccination also resulted in higher risks of high fever, localized redness and swelling, localized induration, and allergic rash compared with DTaP-IPV/Hib vaccination. The risk of AEFI, which were mostly mild reaction, was higher after vaccination with DTaP+IPV+Hib than after DTaP-IPV/Hib vaccination.

Thailand has incorporated the whole-cell (wP) pertussis vaccine into the expanded program on immunization since 1977 and has offered the acellular pertussis (aP) vaccine as an optional vaccine for infants since 2001. We followed healthy children from a clinical trial (ClinicalTrials.gov NCT02408926) in which children were randomly assigned to receive either pentavalent (DTwP-HB-Hib) or hexavalent (DTaP-IPV-HB-Hib) vaccines for their primary series (administered at 2, 4, and 6 months) and first booster vaccination (18 months). Both groups received Tdap-IPV as a second booster at the age of 4 y. Blood samples were collected for evaluation of antibody persistence to diphtheria toxoid (DT), tetanus toxoid (TT), and Bordetella pertussis ( B. pertussis ) between 2 and 6 y of age annually, and for the immunogenicity study of Tdap-IPV at 1 month after the second booster. Antibody persistence to Haemophilus influenzae type b (Hib) was followed until 3 y of age. A total of 105 hexavalent-vaccinated children and 91 pentavalent-vaccinated children completed this study. Both pentavalent and hexavalent groups demonstrated increased antibody levels against DT, TT, and B. pertussis antigens following the second booster with Tdap-IPV. All children achieved a seroprotective concentration for anti-DT and anti-TT IgG at 1 month post booster. The hexavalent group possessed significantly higher anti-pertactin IgG (adjusted p  = .023), whereas the pentavalent group possessed significantly higher anti-pertussis toxin IgG (adjusted p  < .001) after the second booster. Despite declining levels post-second booster, a greater number of children sustained protective levels of anti-DT and anti-TT IgG compared to those after the first booster.

Background: Maternal pertussis vaccination with Tdap vaccine is recommended to protect newborns from severe postnatal infection. HIV-exposed uninfected (HEU) infants have a higher incidence of pertussis infection and may particularly benefit from maternal immunization. The impact of HIV infection on the quality of IgG and memory B cell (MBC) responses to Tdap vaccination in pregnant women (PW) living with HIV (PWH) is unknown., Methods: In this observational study, humoral immune responses to Tdap vaccination, including IgG levels, Fc-dependent effector functions, and MBC frequencies, were measured before and after vaccination in 40 PWH and 42 HIV-uninfected PW. Placental transfer of IgG and avidity were assessed in cord blood (CB). Soluble and cellular immune activation markers were quantified at baseline., Findings: One month after vaccination, PWH had lower frequencies of MBC compared with HIV-uninfected PW. At delivery, PWH had attenuated pertussis-specific IgG levels and Fc-dependent effector functions. Reduced levels of maternal vaccine polyfunctional IgG and IgG avidity were transferred to HEU as compared to HIV-unexposed newborns. After adjustment with ethnicity, maternal antibody levels and gestational age at vaccination, HIV infection was independently associated with decreased levels of PT specific-IgG in CB. Both maternal and neonatal pertussis-specific IgG responses as well as PT-specific IgG avidity were inversely correlated with maternal sCD14 levels before vaccination among PWH., Interpretation: Maternal HIV infection is associated with attenuated humoral immune responses to Tdap vaccination that correlate with sCD14. Suboptimal transfer of maternal immunity may further increase the risk of severe pertussis infection in HEU infants., Funding: This work was supported by IRIS Fund managed by the Foundation Roi Baudouin [2017J1820690206902], Association Vésale pour la Recherche Médicale and the Medical Council of CHU Saint-Pierre and has been funded in part with Federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, US Department of Health and Human Services, under Award No. U19AI145825. N.D. is a clinical researcher and A.M. is Research Director at the Fonds de la Recherche Scientifique (F.R.S.-FNRS), Belgium. M.E.A. was partially supported by NIHNIAID1U19AI14825. This article is published with the support of the Fondation Universitaire of Belgium., Competing Interests: Declaration of interests Y.J reports support from the F.R.S-FNRS. N.D. reports grant support from MSD, honoraria from Boerhingher Ingelheim, and support for attending meetings and/or travel from MSD, ViiV healthcare and Eumedica, all unrelated to the present work. D.K reports honoraria from MSD, ViiV, Janssens, support for attending meetings and/or travel from Gilead, Pfizer, MSD, ViiV and Janssens, participation on advisory board for MSD, all unrelated to the present work. M.A. reports grants from NIH, Bill and Melinda Gates Foundation, SD Ireland Foundation, consulting fees from Seromyx systems and support for attending meetings and/or travel from Keystone conferences, Bill and Melinda Gates., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Global pediatric immunization programs with pneumococcal conjugate vaccines (PCVs) have reduced vaccine-type pneumococcal disease, but a substantial disease burden of non-PCV serotypes remains., Methods: This phase 3, randomized (1:1), double-blind study evaluated safety and immunogenicity of 20-valent PCV (PCV20) relative to 13-valent PCV (PCV13) in healthy infants. Participants received 2 infant doses and a toddler dose of PCV20 or PCV13, with diphtheria-tetanus-acellular pertussis combination vaccine at all doses and measles, mumps, rubella and varicella vaccines at the toddler dose. Primary pneumococcal immunogenicity objectives were to demonstrate noninferiority (NI) of PCV20 to PCV13 for immunoglobulin G geometric mean concentrations after infant and toddler doses and percentages of participants with predefined serotype-specific immunoglobulin G concentrations after infant doses. Safety endpoints included local reactions, systemic events and adverse events., Results: Overall, 1204 participants were vaccinated (PCV20, n = 601; PCV13, n = 603). One month after the toddler dose, 19/20 serotypes met NI for immunoglobulin G geometric mean concentrations; serotype 6B narrowly missed NI [PCV20/PCV13 geometric mean ratio: 0.57 (2-sided 95% confidence interval: 0.48-0.67); NI criterion: lower 2-sided 95% confidence interval >0.5]. Sixteen/twenty serotypes met NI for ≥1 primary objective after 2 infant doses. PCV20 induced robust opsonophagocytic activity, and boosting responses were observed for all vaccine serotypes, including those missing statistical NI. The safety/tolerability profile of PCV20 was like that of PCV13., Conclusions: PCV20 3-dose series in infants was safe and elicited robust immune responses. Based on these results and PCV13 experience, PCV20 3-dose series is expected to be protective for all 20 vaccine serotypes. NCT04546425., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: This study aimed to evaluate the rates of vaccination against infectious diseases (Tetanus, Diphtheria, and Pertussis [Tdap] and influenza) in pregnancy during the coronavirus disease 2019 (COVID-19) pandemic compared to contemporary historical controls., Study Design: This was a retrospective cohort study comparing rates of Tdap and influenza vaccination in pregnant people who received care at NYU Langone Health and delivered from September 1, 2020, to January 31, 2021 ("COVID cohort") to the same period the prior year ("2019 cohort"). Demographic information, trimester of initiation of prenatal care, insurance status, and medical comorbidities were evaluated. Outcomes were analyzed using chi-square, Fisher's exact test, and multivariable logistic regression, with significance of p  < 0.05., Results: In total, 1,713 pregnant people were included. Compared to historical controls, the COVID cohort differed in age, race, timing of initiation of prenatal care, insurance status, and medical comorbidities. After adjusting for these covariates, pregnant people were significantly more likely to accept influenza vaccine in the COVID cohort (adjusted odds ratio [aOR] 1.7, 95% confidence interval [CI] 1.27-2.29) and had similar Tdap acceptance (aOR 1.5, 95% CI 0.99-2.17). However, this trend was not observed for the entire obstetric population; public insurance status and medical comorbidities were associated with lower vaccine rates during the pandemic. For those who had public insurance, rates of influenza vaccination decreased from 83% in 2019 to 40% during COVID (aOR 0.16, 95% CI 0.10-0.24) and for Tdap rates decreased from 93 to 54% (aOR 0.13, 95% CI 0.08-0.21)., Conclusion: During the COVID-19 pandemic era, pregnant people at large were more likely to accept the influenza vaccine. However, this trend did not apply to Tdap, and high-risk groups with public insurance and medical comorbidities. This study highlights potential disparities in vaccination rates, which need to be accounted for when evaluating national vaccine trends. These data support increased efforts in vaccine counseling for high-risk populations., Key Points: · Antenatal flu vaccination increased during the pandemic.. · Antenatal Tdap vaccination was unchanged during the pandemic.. · High-risk pregnant patients had decreased vaccine uptake.. · High-risk subgroups were not included in overarching vaccination trends.., Competing Interests: None declared., (Thieme. All rights reserved.)

Importance: Pregnancy represents a window of opportunity for vaccination due to established maternal and fetal benefits of vaccination. Little is known about receipt of routinely recommended vaccines in pregnancy, specifically tetanus, diphtheria, plus acellular pertussis (Tdap) and influenza, among pregnant people living with HIV (PLHIV)., Objective: To estimate prevalence of vaccination receipt among pregnant people with HIV (PLHIV) and identify demographic and clinical characteristics associated with vaccination., Design, Setting, and Participants: This multicenter cohort study included women participating in Women's Health Study (WHS) of the Surveillance Monitoring for ART Toxicities (SMARTT) Study of the Pediatric HIV/AIDS Cohort Study. The network has been enrolling pregnant PLHIV at 22 US sites since 2007. Participants for this study enrolled between December 2017 and July 2019. Data analysis was conducted from October 2021 to March 2022., Exposure: Data on vaccination in pregnancy were collected through medical record abstraction., Main Outcomes and Measures: Vaccination receipt was defined as Tdap vaccination received at less than 36 weeks' gestation and influenza vaccination at any gestational age, based on current guidelines. Log-binomial and modified Poisson regression models with generalized estimating equations were fit to identify factors associated with successful receipt of (1) Tdap, (2) influenza, and (3) both vaccinations., Results: A total of 310 pregnancies among 278 people participating in the WHS were included (mean [SD] age, 29.5 [6.1] years; 220 [71%] Black, 77 [25%] Hispanic, and 77 [25%] race and ethnicity other than Black; 64 [21%] with perinatally acquired HIV). Less than one-third of pregnancies were vaccinated as recommended (Tdap, 32.6% [95% CI, 27.4%-38.1%]; influenza, 31.6% [95% CI, 26.5%-37.1%]; both, 22.6% [95% CI, 18.0%-27.6%]). People living with perinatally acquired HIV, those who did not identify as Black, or those who were multiparous had adjusted risk ratios (aRRs) less than 1, while older PLHIV had aRRs greater than 1, but these differences did not reach statistical significance (perinatally acquired HIV: adjusted risk ratio [aRR], 0.46; 95% CI, 0.21-1.02; race other than Black: aRR, 0.53; 95% CI, 0.26-1.08; multiparous: aRR, 0.59; 95% CI, 0.35-1.00; age 24-29 years: aRR, 2.03; 95% CI, 0.92-4.48)., Conclusions and Relevance: In this diverse, multicenter cohort of pregnant PLHIV, receipt of recommended vaccinations was low. Identifying and addressing barriers to vaccination receipt is urgently needed for pregnant people with HIV.

Objective: This study examines the impact of the coronavirus disease 2019 (COVID-19) pandemic on influenza and tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine uptake in a pregnant, low-income population., Study Design: This retrospective cohort study included women initiating prenatal care before (May-November 2019) or during the COVID-19 pandemic (May-November 2020) at two large Medicaid clinics. All patients entered prenatal care before 20 weeks and delivered full-term. Medical records were reviewed for vaccine uptake and demographic data. Multivariate logistic regression analysis was used to compare vaccination rates prior to and during the COVID-19 pandemic. Additional analysis was performed to identify association of demographic factors with vaccine uptake. IRB approval was obtained for this study., Results: A total of 939 patients met inclusion criteria, with 462 initiating care prior to and 477 initiating care during the COVID-19 pandemic. Influenza vaccination uptake was 78% (362/462) in the prepandemic group, significantly decreasing to 61% (291/477) in the pandemic group ( p <0.01, odds ratio [OR] = 0.38, confidence interval [CI]: 0.26-0.53). Tdap vaccination uptake was 85% (392/462) in the prepandemic group, significantly decreasing to 76% (361/477) in the pandemic group ( p <0.01, OR = 0.56, CI: 0.40-0.79). The decrease in influenza vaccine uptake was most significant in non-Hispanic Black patients, decreasing from 64% (73/114) in the prepandemic group to 35% (35/101) in the pandemic group ( p <0.01, OR = 0.30, CI: 0.17-0.52), while there was no significant difference in age or parity in relation to vaccination status., Conclusion: Routine vaccination uptake significantly decreased during the COVID-19 pandemic in a low-income population of pregnant women, with decrease more pronounced on influenza vaccine than on Tdap vaccine uptake, especially in non-Hispanic Black patients., Key Points: · Influenza and Tdap vaccination uptake during pregnancy has decreased during the COVID-19 pandemic.. · Influenza vaccine uptake decreased more than Tdap in pregnancy during the COVID-19 pandemic.. · The greatest decrease was seen in influenza vaccine uptake in non-Hispanic Black patients.., Competing Interests: None declared., (Thieme. All rights reserved.)

Objective: This study aims to explore vaccination acceptance among individuals with a history of preterm birth between March and June during the pre-COVID (2019), early-COVID (2020), and late-COVID (2021) periods., Study Design: This is a cross-sectional, retrospective cohort study of pregnant individuals with a history of preterm birth (<37 weeks' gestation) who initiated care of a subsequent pregnancy during pre-COVID (March-June 2019), early-COVID (March-June 2020), or late-COVID (March-June 2021). The primary outcome of interest was vaccination status for influenza, Tdap, and COVID-19 vaccines. Fisher's exact and chi-square tests were used to investigate association between vaccination status and time periods, race/ethnicity, and insurance., Results: Among 293 pregnancies, influenza vaccination rate was highest in early-COVID ( p  < 0.05). There was no statistically significant difference in Tdap or COVID-19 vaccination between time periods. COVID-19 vaccination was highest in individuals with private insurance ( p  < 0.05). There was no statistically significant difference in vaccination status by race/ethnicity., Conclusion: In this study on high-risk pregnant individuals, the majority of our cohort remained unvaccinated against COVID-19 into the late-COVID period. Additionally, their influenza vaccination rates were greater than the national average in early-COVID and substantially lower than the national average in late-COVID. This shift in influenza vaccination acceptance may have been sparked by COVID-19 vaccine distribution beginning in January 2021 leading to overall vaccination hesitancy. Standardized guidelines and counseling concerning prenatal safety in recommended immunizations may serve as important tools of reassurance and health promotion., Key Points: · Maternal infections during pregnancy are a risk factor for preterm birth.. · High-risk cohort had low influenza vaccination post-COVID possibly due to COVID-19 vaccine hesitancy.. · Vaccination education may be a uniquely important tool among high-risk pregnant patients.., Competing Interests: None declared., (Thieme. All rights reserved.)

Objective: COVID-19 vaccination is a key approach to reduce morbidity and mortality in pregnant patients and their newborns. Anti-vaccine sentiment has recently increased with unclear impact on pregnant patients. We examined the association between acceptance of tetanus-diphtheria-acellular pertussis (Tdap) and influenza vaccines, considered to be routine pregnancy vaccines, and COVID-19 vaccine acceptance. Secondarily, we identified other predictors of COVID-19 vaccine uptake and described pregnancy outcomes in patients who were and were not vaccinated during pregnancy., Methods: A retrospective cohort study of all patients who delivered at a single site from December 2020 - March 2022. Demographic, pregnancy, neonatal, and vaccination data were abstracted from the electronic medical record, which imports vaccine history from the California Immunization Registry. The relationship between influenza and Tdap vaccine acceptance, other baseline characteristics, and COVID-19 vaccine uptake was assessed using univariable and multivariable regression analysis., Results: Of the 7857 patients who delivered during the study period, 4410 (56.1%) accepted the COVID-19 vaccine. Of those who received the COVID-19 vaccine, 3363 (97.6%) and 3049 (88.5%) received influenza and Tdap vaccines, respectively. Patients were more likely to receive the COVID-19 vaccine if they had advanced maternal age, obesity, Asian race, and private insurance. After adjustment for baseline differences, COVID vaccine acceptance was associated with receipt of Tdap (aOR 2.10, 95% CI 1.90-2.33) and influenza vaccines (aOR 2.83, 95% CI 2.55-3.14). There were no differences in preterm birth, low birthweight, and NICU admission between patients who received and did not receive the COVID-19 vaccine., Conclusion: Patients were more likely to accept COVID-19 vaccination if they received Tdap or influenza vaccinations. Older age, obesity, Asian race, and private insurance were independent predictors of vaccine uptake. Disparities in COVID-19 vaccination uptake bear further exploration to guide efforts in equitable and widespread vaccine distribution., 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 © 2023 The British Infection Association. Published by Elsevier Ltd. All rights reserved.)

Background: This study assessed the safety and immunogenicity of a new booster vaccine against tetanus, diphtheria, and pertussis manufactured by Serum Institute of India Pvt. Ltd (SIIPL Tdap)., Methods: The Phase II/III trial was randomized (2:1), observer blinded and active controlled. Healthy subjects aged 4-65 years received a single dose of either SIIPL Tdap or comparator Tdap vaccine (Boostrix®, GlaxoSmithKline, Belgium), and were followed-up for 30 days. Blood samples for safety and immunogenicity assessments were collected pre-vaccination and on day 30 post-vaccination. The study assessed safety and reactogenicity of SIIPL Tdap compared to the comparator Tdap as well as the co-primary immunogenicity outcomes: (i) seroprotection rates against diphtheria toxoid (DT) and tetanus toxoid (TT) and (ii) the booster response rates against pertussis toxoid (PT), filamentous hemagglutinin (FHA) and pertactin (PRN) 30 days post-vaccination in all study subjects. A margin of -10 % was used for non-inferiority testing. Secondary outcomes included the booster response rates against DT and TT, seropositivity rates against pertussis antigens, and antibody geometric mean concentrations (GMCs) for all vaccine components., Results: At Day 30 post-vaccination, SIIPL Tdap was assessed as non-inferior to the comparator Tdap in terms of: i) seroprotection rates against DT (94.4 % vs. 94.9 %) and TT (99.9 % vs. 100 %) and ii) pertussis booster response rates (93.8 % vs. 88.4 % anti-PT, 89.7 % vs. 90.9 % anti-FHA and 86.3 % vs. 84.4 % anti-PRN), for SIIPL Tdap versus comparator Tdap, respectively. GMCs for anti-PT and anti-PRN were higher in subjects vaccinated with SIIPL Tdap compared to comparator Tdap. All other secondary outcomes were comparable. The overall frequency of local and systemic solicited AEs was comparable; no treatment related SAEs were reported., Conclusions: Booster vaccination with SIIPL Tdap was non-inferior to comparator Tdap with respect to the immunogenicity of the vaccine components and was equally well tolerated. EudraCT number: 2019-002706-46., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: IA, MM, FP, NMM, LG reports a relationship with Serum Institute of India Pvt Ltd that includes: consulting or advisory. SP, PP, SS, SD, HS, HR, MG, SG, US reports a relationship with Serum Institute of India Pvt Ltd that includes: employment., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

An antenatal pertussis vaccination programme was introduced in 2012 in the UK in the context of a national outbreak of pertussis. It has been shown that a lower antibody response to primary immunisation can be seen for certain pertussis antigens in infants born to women who received pertussis-containing antenatal vaccines, a phenomenon known as blunting. The longer-term impact of this has not been documented previously, and accordingly was evaluated in this study. Children were predominantly recruited from a previous study in which their mothers had received acellular pertussis-containing antenatal vaccines (dTaP 3 -IPV [diphtheria toxoid, tetanus toxoid, three antigen acellular pertussis and inactivated polio] or dTaP 5 -IPV [diphtheria toxoid, tetanus toxoid, five antigen acellular pertussis and inactivated polio]), or no pertussis-containing vaccine. Blood samples were obtained prior to and one month after the acellular pertussis-containing preschool booster (dTaP 5 -IPV) was given at around age 3 years 4 months. Pre- and post-booster immunoglobulin G (IgG) geometric mean concentrations (GMCs) against pertussis toxin, filamentous haemagglutinin, fimbriae 2 & 3, and pertactin, were compared. Prior to the receipt of the preschool booster, there was no difference in the IgG GMCs against pertussis-specific antigens between children born to women vaccinated with dTaP 3 -IPV and dTaP 5 -IPV; however, IgG GMCs against pertussis toxin were significantly lower in children born to women vaccinated with dTaP 3 -IPV compared with children born to unvaccinated women (geometric mean ratio 0.42 [95 % CI 0.22-0.78], p = 0.03). One month after the receipt of the preschool booster there was no differences between the groups. The blunting effect of antenatal pertussis vaccine on pertussis responses in children can persist until preschool age, although it is overcome by the administration of a booster dose. ClinicalTrials.gov registration number: NCT03578120., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: ‘Matthew Snape is the director of NISEC, and Paul Heath and Bassam Hallis are members of the NISEC steering committee, but none of them have received any personal funding from NISEC. Christine Jones and Paul Heath have conducted studies on behalf of St George’s University of London (Paul Heath), University of Southampton (Christine Jones) and University Hospital Southampton NHS Foundation Trust (Christine Jones), funded by vaccine manufacturers, including Glaxo Smith Kline (Paul Heath), Medicago (Christine Jones), MinervaX (Christine Jones, Paul Heath), Moderna (Christine Jones), Novovax (Christine Jones), Pfizer (Christine Jones) and ReViral (Christine Jones) within the last three years, but received no personal funding from these sources. Christine Jones has carried out consultancy or been a member of an advisory board or data safety and monitoring board for Moderna, MSD, Pfizer, and Sanofi in the last three years, and she has received remuneration for these activities.’, (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Organophosphate esters (OPEs) are commonly applied as flame retardants and plasticizers. Toxicological studies suggest exposure effects on immune endpoints, raising concerns as infants' OPE exposures are elevated compared to older children and adults due to hand-to-mouth behavior and breastfeeding. Here, we sought to evaluate the immune responsiveness of infants to a neoantigen (e.g., a newly encountered antigen) in the presence of OPE exposures. As a proxy for immune responsiveness, children were given three doses of the Diphtheria, Tetanus, and Pertussis (DTaP) vaccine as recommended, and diphtheria and tetanus antibodies were evaluated in serum samples collected when children were 12 months old (n = 84). Titers were compared, based on maximum sample overlap, to measurements of OPE metabolites in spot urine samples collected before vaccination (age 2 months, n = 73) and at the time of antibody assessment (12 months of age, n = 46). Metabolites of two chlorinated OPEs were significantly associated with diminished antibodies for diphtheria and tetanus. A metabolite of tris (1,3-dichloroisopropyl)phosphate (TDCIPP) measured at 2 months was associated with decreased diphtheria antibodies (-0.07 IU/mL per log 10 increase in metabolite). One metabolite of tris(2-chloroisopropyl)phosphate (TCIPP) measured at 12 months was associated with decreased tetanus antibodies (-0.57 IU/mL per log 10 increase in metabolite). These results provide some preliminary insights for OPE exposure impacts on vaccine responses in early life and may have important implications for immune health through childhood and adulthood., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kate Hoffman reports financial support was provided by The Gerber Foundation., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Prevention of respiratory syncytial virus (RSV) disease in infants is an unmet vaccine need, and maternal immunization is a potential strategy to address this need. This study evaluated concomitant administration of RSV stabilized prefusion F subunit vaccine (RSVpreF) and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine adsorbed (Tdap) in healthy, nonpregnant women 18‒49 years of age., Methods: In this phase 2b, multicenter, placebo-controlled, observer-blind, noninferiority study, participants were randomized to receive RSVpreF in a range of doses and formulations with Tdap or alone, or Tdap alone. Safety and immunogenicity were assessed., Results: Local reactions and systemic events were generally similar across vaccine groups. Noninferiority of anti-RSV-A and anti-RSV-B immune responses induced by RSVpreF with Tdap was demonstrated compared to RSVpreF alone. Noninferiority of anti-diphtheria toxoid and anti-tetanus toxoid immune responses after administration of RSVpreF with Tdap was demonstrated compared to Tdap alone; noninferiority was not met for anti-pertussis component responses., Conclusions: RSVpreF was safe and well tolerated when administered with Tdap or alone in nonpregnant women 18‒49 years of age. Immune responses induced by Tdap administered with RSVpreF were noninferior for the tetanus and diphtheria components of Tdap, but not for pertussis., Clinical Trials Registration: NCT04071158., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: Between May 2005 and March 2007, three vaccines were recommended by the Advisory Committee on Immunization Practices for routine use in adolescents in the United States: quadrivalent meningococcal conjugate vaccine (MenACWY), tetanus, diphtheria and acellular pertussis vaccine (Tdap), and human papillomavirus vaccine (HPV). Understanding historical adolescent vaccination patterns may inform future vaccination coverage efforts for these and emerging adolescent vaccines, including COVID-19 vaccines., Methods: This was a descriptive, retrospective cohort study. All vaccines administered to adolescents aged 11 through 18 years in the Vaccine Safety Datalink population between January 1, 2007 and December 31, 2016 were examined. Vaccination coverage was assessed by study year for ≥1 dose Tdap or Td, ≥1 dose Tdap, ≥1 dose MenACWY, ≥1 dose HPV, and ≥3 dose HPV. The proportion of vaccine visits with concurrent vaccination (≥2 vaccines administered at the same visit) was calculated by sex and study year. The most common vaccine combinations administered in the study population were described by sex for two time periods: 2007-2010 and 2011-2016., Results: The number of 11-18-year-olds in the study population averaged 522,565 males and 503,112 females per study year. Between January 2007 and December 2016 there were 4,884,553 vaccine visits in this population (45% among males). The overall proportion of concurrent vaccine visits among males was 43% (33-61% by study year). Among females, 39% of all vaccine visits included concurrent vaccination (32-48% by study year). Vaccine coverage for Tdap, MenACWY, and 1- and 3-dose HPV increased across the study period. A wide variety of vaccine combinations were administered among both sexes and in both time periods., Conclusions: The high vaccine uptake and multitude of vaccine combinations administered concurrently in the adolescent population of the Vaccine Safety Datalink provide historical patterns with which to compare future adolescent vaccination campaigns., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ms. Irving, Ms. Groom, Ms. Dandamudi, Drs. Daley, Myers, Stokley and Ms. Gee have no conflicts to report. Dr. Donahue reports receiving grants from Janssen Vaccines & Prevention outside the submitted work. Dr. Hechter reports grants from Gilead Science Inc and Novartis for research studies outside the submitted work. Dr. Jackson reports an organization research contract with Pfizer, outside the submitted work. Dr. Klein reports grants from Pfizer, Merck, GlaxoSmithKline, Sanofi Pasteur, and Protein Sciences (now Sanofi Pasteur), outside the submitted work. Dr. Liles reports research funding from Merck, Pfizer, Epigenomics, and Medical Solutions, outside the submitted work., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objective: Severe pertussis infection has been reported in infants before receiving routine immunization series. This problem could be solved by vaccinating mothers during pregnancy or children at birth. This study aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) and real-world evidence to evaluate the optimal strategy for pertussis vaccination., Data Sources: PubMed, Embase, and the Cochrane Library databases were searched until December 2020., Study Eligibility Criteria: RCTs, cohort studies, case-control studies, and case series were included if they investigated the efficacy, immunogenicity, and safety of acellular pertussis vaccine during pregnancy and at birth., Methods: Number of pertussis cases, severe adverse events (SAEs), and pertussis antibody concentration in infants before and after they receive routine vaccination series were extracted and random-effect model was used to pool the analyses., Results: Overall, 29 studies were included. Our meta-analysis revealed that pertussis immunization during pregnancy significantly increased the concentrations of 3 pertussis antibodies and reduced the incidence rates of infected infants below 3 months of age (odds ratio, 0.22; 95% confidence interval, 0.14-0.33). Similarly, infants vaccinated at birth had higher levels of pertussis antibody than those who were not. No significant difference in rates of severe adverse events was seen in all vaccination groups (during pregnancy [risk ratio, 1.18; 95% confidence interval, 0.76-1.82] and at birth [risk ratio, 0.72; 95% confidence interval, 0.34-1.54])., Conclusion: Pertussis vaccination during pregnancy could protect infants against pertussis disease before the routine vaccination. Pertussis immunization at birth would be an alternative for infants whose mothers did not receive pertussis vaccines during pregnancy., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Neonatal pertussis can potentially cause severe complications and even death. Mothers have been most frequently identified as the source of neonatal pertussis. Approximately a dozen countries have implemented pertussis vaccination programs for pregnant women to protect neonates; however, in Japan, this has not been implemented. The aim of this questionnaire-based study was to ascertain the willingness of women to be vaccinated during pregnancy and the factors associated with willingness. The subjects were 977 pregnant women who visited either of the two selected hospitals for maternity health checks. Most of the women were in their first pregnancy (96%), and approximately half of them considered a physician to be the most reliable source of information about vaccination (481/977, 49%). "Willingness to receive pertussis vaccination" was significantly associated with the factors "no fear of receiving vaccination" (odds ratio [OR] = 3.10, 95% confidence interval [CI]: 2.21-4.34), "necessary to prevent pertussis" (OR = 8.70, 95% CI: 6.17-12.28), "effective in pregnancy" (OR = 5.46, 95% CI: 3.94-7.56), and "no concern about the side effects after vaccination" (OR = 3.03, 95% CI: 1.66-5.55). Pregnant women are likely to consider vaccination if they have a good understanding of the disease and its outcomes. Physicians are well positioned to improve knowledge and attitudes toward pertussis vaccination during pregnancy.

Pertussis is a respiratory disease caused by the Gram-negative pathogen, Bordetella pertussis. The transition from a whole-cell pertussis vaccine (wP and DTP) to an acellular pertussis vaccine (aP, DTaP, and Tdap) correlates with an increase in pertussis cases, despite widespread vaccine implementation and coverage, and it is now appreciated that the protection provided by aP rapidly wanes. To recapitulate the localized immunity observed from natural infection, mucosal vaccination with aP was explored using the coughing rat model of pertussis. Overall, our goal was to evaluate the route of vaccination in the coughing rat model of pertussis. Immunity induced by both oral gavage and intranasal vaccination of aP in B. pertussis challenged rats over a 9-day infection was compared to intramuscular wP (IM-wP)- and IM-aP-immunized rats that were used as positive controls. Our data demonstrate that mucosal immunization of aP resulted in the production of anti- B. pertussis IgG antibody titers similar to IM-wP- and IM-aP-vaccinated controls postchallenge. IN-aP also induced anti- B. pertussis IgA antibodies in the nasal cavity. Immunization with IM-wP, IM-aP, IN-aP, and OG-aP immunization protected against B. pertussis -induced cough, whereas OG-aP immunization did not protect against respiratory distress. Mucosal immunization by both intranasal and oral gavage administration protected against acute inflammation and decreased bacterial burden in the lung compared to mock-vaccinated challenge rats. The data presented in this study suggest that mucosal vaccination with aP can induce a mucosal immune response and provide protection against B. pertussis challenge. This study highlights the potential benefits and uses of the coughing rat model of pertussis; however, further questions regarding waning immunity still require additional investigation.

Tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine is generally used for booster vaccination of infants in Europe and the United States to avoid increased reactogenicity after diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccination. However, Japan has extended the use of additional DTaP vaccination without reducing the antigen dose for diphtheria and pertussis in adolescents and adults, despite limited reports on its safety in adults. This prospective, observational, questionnaire-based study investigated the occurrence of adverse events (AEs) following DTaP vaccination between June 2018 and June 2019 in participants aged 10 years or older. Of the 250 eligible participants, 235 (94%) responded regarding AEs. Among them, 133 (56.6%) reported AEs, of which 39 reported systemic AEs (16.6%) and 120 reported local AEs (51.1%) attributed to DTaP vaccination. The incidence of local AEs was markedly higher with DTaP vaccination than with non-DTaP vaccination (51.1% vs. 10.5%), and AEs appeared later (P < 0.01) and lasted longer (P < 0.01) with DTaP vaccination. However, more than 75% of these AEs resolved within 7 days. DTaP vaccination was not associated with any serious AEs. These results indicate that the DTaP vaccine can be widely used as a booster in adults as an alternative to the Tdap vaccine.

The Advisory Committee on Immunization Practices (ACIP) recommends that adolescents aged 11-12 years routinely receive tetanus, diphtheria, and acellular pertussis (Tdap); meningococcal conjugate (MenACWY); and human papillomavirus (HPV) vaccines. Catch-up vaccination is recommended for hepatitis B (HepB); hepatitis A (HepA); measles, mumps, and rubella (MMR); and varicella (VAR) vaccines for adolescents whose childhood vaccinations are not current. Adolescents are also recommended to receive a booster dose of MenACWY vaccine at age 16 years, and shared clinical decision-making is recommended for the serogroup B meningococcal vaccine (MenB) for persons aged 16-23 years (1). To estimate coverage with recommended vaccines, CDC analyzed data from the 2020 National Immunization Survey-Teen (NIS-Teen) for 20,163 adolescents aged 13-17 years.* Coverage with ≥1 dose of HPV vaccine increased from 71.5% in 2019 to 75.1% in 2020. The percentage of adolescents who were up to date † with HPV vaccination (HPV UTD) increased from 54.2% in 2019 to 58.6% in 2020. Coverage with ≥1 dose of Tdap, ≥1 dose (and among adolescents aged 17 years, ≥2 doses) of MenACWY remained similar to coverage in 2019 (90.1%, 89.3%, and 54.4% respectively). Coverage increased for ≥2 doses of HepA among adolescents aged 13-17 years and ≥1 dose of MenB among adolescents aged 17 years. Adolescents living below the federal poverty level § had higher HPV vaccination coverage than adolescents living at or above the poverty level. Adolescents living outside a metropolitan statistical area (MSA) ¶ had lower coverage with ≥1 MenACWY and ≥1 HPV dose, and a lower proportion being HPV UTD than adolescents in MSA principal cities. In 2020, the COVID-19 pandemic disrupted routine immunization services. Results from the 2020 NIS-Teen reflect adolescent vaccination coverage before the COVID-19 pandemic. The 2020 NIS-Teen data could be used to assess the impact of the COVID-19 pandemic on catch-up vaccination but not on routine adolescent vaccination because adolescents included in the survey were aged ≥13 years, past the age when most routine adolescent vaccines are recommended, and most vaccinations occurred before March 2020. Continued efforts to reach adolescents whose routine medical care has been affected by the COVID-19 pandemic are necessary to protect persons and communities from vaccine-preventable diseases and outbreaks., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Background: Incorporating dengue vaccination into existing childhood vaccination programs could increase vaccine coverage. This study assessed the safety and immunogenicity of concomitant versus sequential administration of the combined tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine and the tetravalent dengue vaccine (CYD-TDV)., Methods: This phase IIIb, randomized, open-label, multicenter study was conducted in the Philippines in individuals 9-≤60 years of age (NCT02992418). Participants were to receive 3 CYD-TDV doses 6 months apart, the first dose administered either concomitantly or sequentially (28 days post-Tdap). Antibody levels were measured at baseline and 28 days post-first doses of Tdap vaccine and CYD-TDV, using enzyme-linked immunosorbent assay (pertussis, tetanus), micrometabolic inhibition test-toxin neutralization assay (diphtheria) and plaque reduction neutralization test (dengue). Immunogenicity was assessed for all participants, and statistical analysis reported for baseline dengue seropositive participants. Safety was assessed throughout., Results: Among 688 randomized participants, 629 (91.4%) were baseline dengue seropositive (concomitant group, n = 314 and sequential group, n = 315). After the first dose, non-inferiority of immune responses between concomitant and sequential vaccination was achieved; between-group geometric mean antibody concentration ratios were close to 1 for anti-PT, anti-FHA, anti-PRN and anti-FIM, between-group differences in percent achieving seroprotection (titers ≥0.1 IU/mL) were 0.26% (diphtheria) and 0.66% (tetanus), and between-group geometric mean antibody titer ratios were close to 1 for dengue serotypes 1-4. Safety profiles in both study groups were comparable., Conclusions: CYD-TDV and Tdap vaccine administered concomitantly or sequentially in baseline dengue seropositive participants elicited comparable immunogenicity and safety profiles., Competing Interests: T.C.M., C.V., C.Z., M.-L.T. and S.M. are employees of Sanofi Pasteur and may hold shares and/or stock options in the company. The other authors have no conflicts of interest to disclose., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Importance: In most countries, the diphtheria-tetanus-acellular pertussis (DTaP) vaccine is administered as a 3-dose infant series followed by additional booster doses in the first 5 years of life. Short-term immunity from the DTaP vaccine can depend on the number, timing, and interval between doses. Not receiving doses in a timely manner might be associated with a higher pertussis risk., Objective: To examine the association between number and timeliness of vaccine doses and age-specific pertussis risk., Design, Setting, and Participants: This population-based, retrospective cohort study used Washington State Immunization Information System data and pertussis surveillance data from Public Health Seattle and King County, Washington. Included participants were children aged 3 months to 9 years born or living in King County, Washington, between January 1, 2008, and December 31, 2017. Data were analyzed from June 30 to December 1, 2019., Exposures: Being undervaccinated (receiving fewer than recommended doses at a given age) or delayed vaccination (not receiving doses within time frames recommended by Centers for Disease Control and Prevention)., Main Outcomes and Measures: Suspected, probable, and confirmed pertussis diagnosis., Results: A total of 316 404 children (median age, 65.2 months [interquartile range, 35.3-94.1 months]; 162 025 boys [51.2%]) as of December 31, 2017, with 17.4 million person-months of follow-up were included in the analysis. A total of 19 943 children (6.3%) had no vaccines recorded in the Immunization Information System, 116 193 (36.7%) received a vaccine with a delay, and 180 268 (56.9%) were fully vaccinated with no delay. Delayed vaccination and undervaccination rates were higher for older children (17.6% delayed or undervaccinated at age 2 months for dose 1 at 3 months vs 41.6% at age 5 years for dose 5) but improved for successive birth cohorts (52.2% for 2008 birth cohort vs 32.3% for 2017 birth cohort). Undervaccination was significantly associated with higher risk of pertussis for the 3-dose primary series (adjusted relative risk [aRR], 4.8; 95% CI, 3.1-7.6), the first booster (aRR, 3.2; 95% CI, 2.3-4.5), and the second booster (aRR, 4.6; 95% CI, 2.6-8.2). However, delay in vaccination among children who received the recommended number of vaccine doses was not associated with pertussis risk., Conclusions and Relevance: The results of this cohort study suggest that undervaccination is associated with higher pertussis risk. Short delays in vaccine receipt may be less important if the age-appropriate number of doses is administered, but delaying doses is not recommended. Ensuring that children receive all doses of pertussis vaccine, even if there is some delay, is important.

Background: Adult vaccinations may reduce risk for dementia. However, it has not been established whether tetanus, diphtheria, pertussis (Tdap) vaccination is associated with incident dementia., Methods: Hypotheses were tested in a Veterans Health Affairs (VHA) cohort and replicated in a MarketScan medical claims cohort. Patients were at least 65 years of age and free of dementia for 2 years prior to index date. Patients either had or did not have a Tdap vaccination by the start of either of the 2 index periods (2011 or 2012). Follow-up continued through 2018. Controls had no Tdap vaccination for the duration of follow-up. Confounding was controlled using entropy balancing. Competing risk (VHA) and Cox proportional hazard (MarketScan) models estimated the association between Tdap vaccination and incident dementia in all patients and age subgroups (65-69, 70-74, and ≥75 years)., Results: VHA patients were, on average, 75.6 (SD ± 7.5) years of age, 4% female, and 91.2% were White. MarketScan patients were 69.8 (SD ± 5.6) years of age, on average and 65.4% were female. After controlling for confounding, patients with, compared to without, Tdap vaccination had a significantly lower risk for dementia in both cohorts (VHA: hazard ratio [HR] = 0.58; 95% confidence interval [CI]:0.54-0.63 and MarketScan: HR = 0.58; 95% CI:0.48-0.70)., Conclusions: Tdap vaccination was associated with a 42% lower dementia risk in 2 cohorts with different clinical and sociodemographic characteristics. Several vaccine types are linked to decreased dementia risk, suggesting that these associations are due to nonspecific effects on inflammation rather than vaccine-induced pathogen-specific protective effects., (© The Author(s) 2021. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Immunization with tetanus-diphtheria-acellular pertussis (Tdap) vaccine in pregnancy is increasingly recommended. We determined the effect of Tdap immunization in pregnancy on infants' vaccine responses., Methods: Individual-participant data meta-analysis of ten studies (n=1884) investigating infants' antibody response to routine immunizations following Tdap immunization in pregnancy was performed. Geometric mean ratios (GMRs) of antigen-specific immunoglobulin G (IgG) levels were calculated using mixed-effects models. Seroprotection rates were compared using chi-squared tests., Results: Infants of Tdap-immunized women had significantly lower IgG against pertussis toxin (GMR 0.65; 95%CI 0.57-0.74), filamentous haemagglutinin (FHA) (0.68; 0.53-0.87), pertactin (0.65; 0.58-0.72) and fimbria 2/3 (FIM2/3) (0.41; 0.32-0.52) after primary immunization, compared with infants of unimmunized women. These lower levels persisted after booster immunization for FHA (0.72; 0.61-0.84) and FIM2/3 (0.53; 0.29-0.96). After primary immunization, infants of Tdap-immunized women had lower seroprotection rates against diphtheria (90% [843/973] vs 98% [566/579]; p<0.001) and invasive pneumococcal disease (IPD) caused by 5 Streptococcus pneumoniae (SPN) serotypes (SPN5, SPN6B, SPN9V, SPN19A, SPN23F), and higher seroprotection rates against Haemophilus influenzae type b (short-term and long-term seroprotection rates, 86%[471/547] vs 76%[188/247] and 62%[337/547] vs 49%(121/247), respectively, all p=0.001). After booster immunization, seroprotection rates against diphtheria and tetanus were 99% (286/288) and (618/619) in infants of Tdap-immunized women, respectively., Conclusions: Infants of Tdap-immunized women in pregnancy had lower IgG levels against pertussis, diphtheria and some SPN serotypes after their immunization compared with infants of unimmunized women. Enhanced surveillance of pertussis, diphtheria and IPD in infants is needed to determine the clinical significance of these findings., Systematic Review Registration: CRD42017079171., Competing Interests: BA-R is supported by the Canadian Health and Research Institute Vanier Canada Graduate scholarship. KM is the beneficiary of a postdoctoral mandate fellowship from the Fund for Scientific Research-Flanders (FWO 12R5819). MS is supported via salary awards from the BC Children’s Hospital Foundation, the Canadian Child Health Clinician Scientist Program and the Michael Smith Foundation for Health Research. MS has been an investigator on projects funded by GlaxoSmithKline, Merck, Pfizer, Sanofi Pasteur, Seqirus, Symvivo and VBI Vaccines. All funds have been paid to his institute, and he has not received any personal payments. SH has been an investigator on projects funded by GlaxoSmithKline, Merck, Pfizer, Sanofi-Pasteur, and CanSino; all funds have been paid to his University. SH has also served on ad hoc advisory boards for GSK, Sanofi, Pfizer, AsraZeneca, Merck, and IMV. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Abu-Raya, Maertens, Munoz, Zimmermann, Curtis, Halperin, Rots, Barug, Holder, Kampmann, Leuridan and Sadarangani.)

Introduction: The humoral response to vaccinations varies widely between individuals. There is no data available on the correlation between responses to different vaccines. In this study, we investigated the correlation of antibody responses between routine vaccine antigens in infants., Methods: One and seven months after the 6-month vaccinations and one month after the 12-month vaccinations, antibody concentrations to diphtheria, tetanus, pertussis, polio (serotypes 1-3), Haemophilus influenzae type b (Hib), pneumococcus (13 serotypes), meningococcus C, measles, mumps and rubella were measured using fluorescent bead-based multiplex immune-assays. For the correlation of antibody responses, Spearman's rank correlation coefficients (ρ) with 95% confidence intervals (CI) were calculated between responses to each vaccine antigen., Results: The correlation between concentrations of antibodies to the vaccinations ending at 6 months of age was higher one month compared to seven months after vaccination. The strongest correlations at both time points were observed between antibody responses to different polio serotypes, certain pneumococcal serotypes and between responses to diphtheria and pneumococcal (conjugated to a diphtheria toxoid) vaccine antigens. Correlation between responses to tetanus, Hib, pertussis, polio and other vaccine antigens were weak. The correlation between antibody responses to the 12-month vaccine antigens was weaker than to the 6-month vaccine antigens and there was a negative correlation between responses to measles, mumps, rubella vaccine and non-live vaccine antigens (meningococcus C, tetanus and Hib). There was only weak correlation between antibody responses to vaccines of the same type (e.g. conjugated polysaccharide or toxoid vaccines)., Conclusion: Correlation between antibody responses to similar antigens in the same vaccine (such as different serotypes of a bacteria or virus), as well as responses to antigens conjugated to similar carrier proteins, are strong. In contrast, correlation between responses to other vaccines are weak. Measuring antibody responses to one or a few vaccine antigens therefore does not offer a reliable surrogate marker of responses to unrelated vaccines., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zimmermann, Ritz, Perrett, Messina, van der Klis and Curtis.)

Background: The Bacillus Calmette-Guérin (BCG), the only vaccine against tuberculosis (TB) currently in use, has shown beneficial effects against unrelated infections and to enhance immune responses to vaccines. However, there is little evidence regarding the influence of BCG vaccination on pertussis., Methods: Here, we studied the ability of BCG to improve the immune responses to diphtheria, tetanus, and acellular (DTaP) or whole-cell pertussis (DTwP) vaccination in a mouse model. We included MTBVAC, an experimental live-attenuated vaccine derived from Mycobacterium tuberculosis, in our studies to explore if it presents similar heterologous immunity as BCG. Furthermore, we explored the potential effect of routine BCG vaccination on pertussis incidence worldwide., Findings: We found that both BCG and MTBVAC when administered before DTaP, triggered Th1 immune responses against diphtheria, tetanus, and pertussis in mice. Immunization with DTaP alone failed to trigger a Th1 response, as measured by the production of IFN-γ. Humoral responses against DTaP antigens were also enhanced by previous immunization with BCG or MTBVAC. Furthermore, exploration of human epidemiological data showed that pertussis incidence was 10-fold lower in countries that use DTaP and BCG compared to countries that use only DTaP., Interpretation: BCG vaccination may have a beneficial impact on the protection against pertussis conferred by DTaP. Further randomized controlled trials are needed to properly define the impact of BCG on pertussis incidence in a controlled setting. This could be a major finding that would support changes in immunization policies., Funding: This work was supported by the Ministry of "Economía y Competitividad"; European Commission H2020 program, "Gobierno de Aragón"; CIBERES; "Fundação Butantan"; Instituto de Salud Carlos III and "Fondo FEDER"., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: The response to vaccines in juvenile idiopathic arthritis (JIA) patients on and off anti-tumor necrosis factor (anti-TNF) agents remains highly discussed. There are no published studies on the immune response following a Tdap booster dose in JIA patients so far., Objective: To evaluate the immune response and safety after a Tdap booster in JIA patients and in healthy adolescents., Methods: Nineteen adolescents with JIA according to the ILAR criteria on anti-TNF medication, 19 adolescents with JIA off anti-TNF medication, and 27 healthy adolescents (control group) were compared after a Tdap booster. Adverse events and disease activity were evaluated. Lymphocyte immunophenotyping was performed by flow cytometry. Tetanus, diphtheria and pertussis toxin antibodies were assessed by ELISA; whole blood was stimulated with whole-cell pertussis, and supernatants were assessed for cytokines by xMAP., Results: The three groups showed a similar frequency of adverse events. There was no disease reactivation after the Tdap booster. Tetanus, diphtheria and pertussis antibodies showed a significant response when D0 and D14 concentrations were compared in both JIA groups and controls. Over time, a different pattern of response to the Tdap booster was observed among the groups for tetanus antibodies (p = 0.005) but not for diphtheria and pertussis antibodies. In contrast to the protection attained for tetanus and diphtheria, in the three groups, not all individuals showed pertussis seroconversion at either D14 or D28. In addition, the seroconversion of three subjects with JIA on anti-TNF medication was not maintained at D28. JIA patients off anti-TNF showed a higher percentage of naive CD8 + T cells (p = 0.007) and central memory CD8 + cells (p = 0.003) and a lower percentage of effector CD8 + T cells (p = 0.003) and NK cell numbers (p = 0.018) than the control group. The JIA group off anti-TNF medication had fewer B lymphocytes than both the JIA group on anti-TNF medication and the control group (p = 0.016). Cellular immunity to Bordetella pertussis showed that IFNγ levels were significantly lower in both JIA groups than in the control group (p = 0.003), IL10 levels were higher in the JIA off anti-TNF group (p = 0.009), IL17A and IL5 levels were lower in the JIA on anti-TNF group than in the control group (p = 0.018 and p = 0.016, respectively); however, an increase in IFNγ (p = 0.008), IL17A (p = 0.030) and TNFα (p = 0.041) levels was observed at D14 in both patient groups. Both JIA groups showed higher levels of IL21 than the control group (p = 0.023)., Conclusion: We conclude that individuals with JIA on or off anti-TNF agents showed a good response to a booster dose for the three antigens studied in the absence of major adverse events and without the reactivation of the disease., 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 © 2021 Elsevier Ltd. All rights reserved.)

Background: Reports on vaccine responses in immunocompromised patients, such as juvenile systemic lupus erythematosus (jSLE), have shown highly variable results., Objective: To compare the immune response and safety after a Tdap booster in 26 jSLE patients and 26 matched healthy adolescents. Methodology: Adverse events and disease activity were evaluated. Lymphocyte immunophenotyping was performed by flow cytometry. Tetanus, diphtheria and pertussis toxin antibodies were assessed by ELISA; whole blood was stimulated with whole cell pertussis and supernatants were assessed for cytokines by xMAP., Results: Both groups showed a similar frequency of adverse events. There was no evidence of disease reactivation after Tdap booster in the jSLE cohort. Both groups showed a significant increase in antibody titers for all three antigens on D14 and D28 (p < 0.001). jSLE patients had a significantly lower increase in diphtheria titers than the control group (p = 0.007). jSLE patients had a distinct titer increase of tetanus and pertussis antibodies when compared to controls (p = 0.004 and p < 0.001, respectively). There was a lower frequency of pertussis seroconversion in the jSLE group on D14 (p = 0.009), D28 (p = 0.023), D12m (p = 0.015) and D24m (p = 0.004). Cellular immune response to Bordetella pertussis showed significantly lower levels of IFNγ (p < 0.001) and higher levels of IL10, IL12, IL21 and TNFα in jSLE patients than controls., Conclusions: jSLE patients had good response to Tdap booster dose for the tetanus antigen, but not for diphtheria and pertussis. This vaccine was safe in relation to adverse events and absence of disease reactivation.

Pregnant women and their fetuses are among the vulnerable populations that can be severely affected by communicable diseases. As such, some vaccines such as the influenza and the Tdap (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis) vaccines are strongly recommended in each pregnancy, with generally safe profiles. Other vaccines can be offered based on risk factors, and only when the benefits of receiving them outweigh the risks. Development of vaccines against group B streptococcus infection and respiratory syncytial virus infection are of great importance. In this paper, the recommendations for administration of each vaccine during pregnancy are discussed. The FIGO Committee for Safe Motherhood and Newborn Health Committee endorses the recommendations to vaccinate all pregnant women against influenza during the influenza season at any time during the pregnancy and against Tdap preferably between the 27th and 36th weeks of pregnancy in each pregnancy., (© 2020 International Federation of Gynecology and Obstetrics.)

Clostridium tetani causes life-threatening disease by producing tetanus neurotoxin (TeNT), one of the most toxic protein substances. Toxicosis can be prevented and cured by administration of anti-TeNT neutralizing antibodies. Here, we identified a series of monoclonal antibodies (mAbs) derived from memory B cells of a healthy adult immunized with the C-terminal domain of TeNT (TeNT-Hc). Thirteen mAbs bound to both tetanus toxoid (TT) and TeNT-Hc, while two mAbs recognized only TT. VH3-23 was the most frequently used germline gene in these TT-binding mAbs, and the pairwise identity values of the VH gene sequences ranged from 27% to 69%. Three of these mAbs-T3, T7, and T9-6-completely protected mice from challenge with 2× LD 50 of TeNT, and two (T2 and T18) significantly prolonged the survival time. The five neutralizing mAbs recognized distinct epitopes on TT, with binding affinities ranging from 0.123 to 11.9 nM. Our study provides promising therapeutic candidates for tetanus., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: To evaluate whether the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recommended influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccinations in pregnancy are associated with increased risk of stillbirth., Methods: We performed a case-control study in the Vaccine Safety Datalink that was matched 1:4 on site, month, and year of last menstrual period, comparing the odds of vaccination in pregnancies that ended in stillbirth (defined as fetal loss at or after 20 weeks of gestation) compared with those that ended in live birth from January 1, 2012, to September 30, 2015. We included patients with singleton pregnancies that ended in stillbirth or live birth who had at least one prenatal care visit, pregnancy dating information, and continuous health plan enrollment for the duration of pregnancy. Medical records for all stillbirths were reviewed. We were statistically powered to detect an odds ratio (OR) of 1.37 when evaluating the association between influenza or Tdap vaccination and stillbirth. We also examined stillbirth rates in pregnant patients aged 14-49 years in the Vaccine Safety Datalink between 2007 and 2015., Results: In our matched analysis of 795 confirmed stillbirths in the case group and 3,180 live births in the control group, there was no significant association between influenza vaccination during pregnancy and stillbirth (343/795 [43.1%] stillbirths in the case group vs 1,407/3,180 [44.3%] live births in the control group, OR 0.94, adjusted OR 0.95, 95% CI 0.79-1.14, P=.54) and no significant association between Tdap vaccination during pregnancy and stillbirth (184/795 [23.1%] stillbirths in the case group vs 746/3,180 [23.5%] live births in the control group, OR 0.97, aOR 0.96, 95% CI 0.76-1.28, P=.91). From 2007 to 2015, the stillbirth rate in the Vaccine Safety Datalink was 5.2 per 1,000 live births and stillbirths., Conclusion: No association was found between vaccination during pregnancy and the odds of stillbirth. These findings support the safety of ACIP recommendations for vaccination during pregnancy.

Introduction: The objective was to compare incidence rates of pertussis in children under the age of one in Castelló, before and after the introduction of vaccination of pregnant women in January 2015., Methods: The incidence of the post-vaccine period (2015-2018) was compared with the pre-vaccine period (2011-2014) in all ages, in children from 3 to 11 months and under 3 months. The relative risks and their 95% confidence intervals (95% CI) were calculated., Results: The overall rate of pertussis in all ages was higher in the post-vaccine period than in the pre-vaccine period (0.23 vs. 0.15 per 1.000 person-years), but decreased in those under 3 months. The relative risks were: 1.56 (95% CI 1.34-1.82) in all ages; 1.73 (95% CI 0.87-3.57) for children aged 3 to 11 months, and 0.35 (95% CI 0.16-0.69) for children under 3 months. A similar pattern was observed for hospitalised children., Conclusions: The incidence rate in children under 3 months was reduced by 65% in the period after the intervention, and the hospitalisation risk rate by 71%, suggesting that the measure has been effective and specific for this age group., (Copyright © 2020 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

Background and Purpose: Pertussis is a serious infectious disease in young infants, and severe cases frequently cause death. Our study explored risk factors for death from severe pertussis., Method: A case-control study of infants with severe pertussis admitted to the paediatric intensive care unit (PICU) in the Children's Hospital of Chongqing Medical University, China, from January 1, 2013, to June 30, 2019, was conducted. Pertussis was confirmed by clinical features and laboratory examinations. Severe pertussis was defined as patients with pertussis resulting in PICU admission or death. To understand the risk factors for death, we compared fatal and nonfatal cases of severe pertussis in infants aged < 120 days by collecting clinical and laboratory data., Results: The participants included 63 infants < 120 days of age with severe pertussis. Fifteen fatal cases were confirmed and compared with 44 nonfatal severe pertussis cases, Four patients with termination of treatment were excluded. In the univariate analysis, the risk factors associated with death included apnoea (P = 0.001), leukocytosis (white blood cell (WBC) count≥30 × 10 9 /L (P = 0.001) or ≥ 50 × 10 9 /L (P = 0)), highest lymphocyte count (P = 0), pulmonary hypertension (P = 0.001), and length of PICU stay (P = 0.003). The multivariate analysis revealed that apnoea (OR 23.722, 95%CI 2.796-201.26, P = 0.004), leukocytosis (OR 63.708, 95%CI 3.574-1135.674, P = 0.005) and pulmonary hypertension (OR 26.109, 95%CI 1.800-378.809, P = 0.017) were significantly associated with death., Conclusion: Leukocytosis and pulmonary hypertension exhibited the greatest associations with death in infants with severe pertussis admitted to the PICU. Vaccination is still the most effective protection method against pertussis.

To capture strategies for achieving high adolescent coverage of tetanus-diphtheria-acellular pertussis (Tdap), meningococcal conjugate (MenACWY), and human papillomavirus (HPV) vaccination, we surveyed employees of 20 North Carolina (N.C.) clinics that achieved adolescent vaccination coverage higher than the state average. One employee per clinic completed a surveysummarizing clinic practices regarding adolescent vaccination; perceived barriers and facilitators to Tdap/MenACWY/HPV vaccination; and the role of "champions" who made special efforts to promote adolescent vaccination. Common perceived barriers for all vaccinations were parental opposition and logistical barriers to receiving vaccination. For HPV vaccination, employees cited parental concerns about sexual behavior and injection site pain; no school vaccination requirement; and low-perceived benefit in boys. Most clinics (80%) implemented successful changes to increase adolescent vaccination: consistently offering vaccination, tracking vaccination status using existing data, providing appointment reminders, updating providers on vaccination recommendations, and expanding vaccination hours. Strategies to improve HPV vaccination included co-administration with Tdap and MenACWY, and providing reminders to complete the vaccination series. Vaccine champions strongly recommended vaccination to parents (55%) and educated parents on vaccination recommendations (36%). Clinics in N.C.and similar settings can implement these and other low-resource strategies to overcome adolescent vaccination barriers., Abbreviations: CDC=Centers for Disease Control and Prevention; EHR=Electronic health record; HPV=Human papillomavirus; Tdap=Tetanus-diphtheria-acellular pertussis vaccine; MenACWY=Meningococcal Conjugate Vaccine; NCIB=North Carolina Immunization Branch; NCIR=North Carolina Immunization Registry; ACIP=Advisory Committee on Immunization Practices.

The introduction of treatment and systematic vaccination has significantly reduced diphtheria mortality; however, toxigenic strains continue to circulate worldwide. The emergence of an indigenous diphtheria case with fatal outcome in Greece, after 30 years, raised challenges for laboratory confirmation, clinical and public health management. Toxigenic Corynebacterium diphtheriae was isolated from an incompletely vaccinated 8-year-old boy with underlying conditions. The child passed away due to respiratory distress syndrome, before the administration of diphtheria antitoxin (DAT). All close contacts in family, school and hospital settings were investigated. Pharyngeal swabs were obtained to determine asymptomatic carriage. Chemoprophylaxis was given for 7 days to all close contacts and a booster dose to those incompletely vaccinated. Testing revealed a classmate, belonging to a subpopulation group (Roma), and incompletely vaccinated, as an asymptomatic carrier with an indistinguishable toxigenic strain (same novel multilocus sequence type, designated ST698). This case highlights the role of asymptomatic carriage, as the entry of toxigenic strains into susceptible populations can put individuals and their environment at risk. Maintenance of high-level epidemiological and microbiological surveillance, implementation of systematic vaccination in children and adults with primary and booster doses, availability of a DAT stockpile, and allowing timely administration are the cornerstone to prevent similar incidents in the future.

Background: The Canadian National Advisory Committee on Immunization recommends universal vaccination against pertussis in pregnancy. We assessed the cost-effectiveness of vaccination with tetanus-diphtheria-acellular pertussis (Tdap) vaccine in pregnancy in Canada., Methods: We conducted a cost-utility analysis comparing a vaccination program to no program corresponding with the 2017 Canadian guideline for economic evaluation from the Canadian Agency for Drugs and Technologies in Health. We developed 2 models - part decision tree, part Markov model - to estimate the long-term cost and quality-adjusted life-years (QALYs) for pregnant women and their infants. We obtained epidemiologic data from 2006 to 2015, and derived costs and utility values from relevant sources. Results were reported in 2019 Canadian dollars. We obtained expected values through probabilistic analysis, with methodologic and structural uncertainty assessed through scenario analyses. The analysis adopted an acquisition price of Tdap vaccine of $12.50, with scenario analysis conducted to identify the threshold price for vaccination to be cost-effective., Results: In the base-case scenario, for every 1000 pregnant women vaccinated, the program would lead to a gain of 0.3 QALYs, occurring solely in infants, at an increased total cost of $12 987, or $44 301 per QALY gained. Based on a threshold of $50 000 per QALY gained, vaccination would have been cost-effective in 6 of the 10 years included in the model (range of incremental costs $20 463-$100 348 per QALY gained). The threshold cost for Tdap vaccine to be cost-effective over the 10-year horizon was $14.03., Interpretation: Based on a threshold of $50 000 per QALY gained, vaccination against pertussis in pregnancy would be cost-effective if the acquisition cost per vaccine were $14.03 or less. Province- and territory-specific analyses should be done to inform local decision-making., Competing Interests: Competing interests: Manish Sadarangani is supported via salary awards from the BC Children’s Hospital Foundation, the Canadian Child Health Clinician Scientist Program and the Michael Smith Foundation for Health Research. He has been an investigator on projects funded by Merck, VBI Vaccines, Pfizer, Seqirus, Sanofi Pasteur and GlaxoSmithKline; all funds have been paid to his institute, and he has not received any personal payments. Scott Halperin has been an investigator on projects funded by Merck, VBI Vaccines, Pfizer, Seqirus, Sanofi Pasteur and GlaxoSmithKline, and has served on ad hoc advisory boards for Merck, Sanofi Pasteur, GlaxoSmithKline and Pfizer; all funds have been paid to his university, and he has not received any personal payments. No other competing interests were declared., (Copyright 2020, Joule Inc. or its licensors.)

Vaccination of pregnant women with influenza vaccine and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) can decrease the risk for influenza and pertussis among pregnant women and their infants. The Advisory Committee on Immunization Practices (ACIP) recommends that all women who are or might be pregnant during the influenza season receive influenza vaccine, which can be administered at any time during pregnancy (1). ACIP also recommends that women receive Tdap during each pregnancy, preferably during the early part of gestational weeks 27-36 (2,3). Despite these recommendations, vaccination coverage among pregnant women has been found to be suboptimal with racial/ethnic disparities persisting (4-6). To assess influenza and Tdap vaccination coverage among women pregnant during the 2019-20 influenza season, CDC analyzed data from an Internet panel survey conducted during April 2020. Among 1,841 survey respondents who were pregnant anytime during October 2019-January 2020, 61.2% reported receiving influenza vaccine before or during their pregnancy, an increase of 7.5 percentage points compared with the rate during the 2018-19 season. Among 463 respondents who had a live birth by their survey date, 56.6% reported receiving Tdap during pregnancy, similar to the 2018-19 season (4). Vaccination coverage was highest among women who reported receiving a provider offer or referral for vaccination (influenza = 75.2%; Tdap = 72.7%). Compared with the 2018-19 season, increases in influenza vaccination coverage were observed during the 2019-20 season for non-Hispanic Black (Black) women (14.7 percentage points, to 52.7%), Hispanic women (9.9 percentage points, to 67.2%), and women of other non-Hispanic (other) races (7.9 percentage points, to 69.6%), and did not change for non-Hispanic White (White) women (60.6%). As in the 2018-19 season, Hispanic and Black women had the lowest Tdap vaccination coverage (35.8% and 38.8%, respectively), compared with White women (65.5%) and women of other races (54.0%); in addition, a decrease in Tdap vaccination coverage was observed among Hispanic women in 2019-20 compared with the previous season. Racial/ethnic disparities in influenza vaccination coverage decreased but persisted, even among women who received a provider offer or referral for vaccination. Consistent provider offers or referrals, in combination with conversations culturally and linguistically tailored for patients of all races/ethnicities, could increase vaccination coverage among pregnant women in all racial/ethnic groups and reduce disparities in coverage., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

CenteringPregnancy, an alternative to traditional prenatal care, offers additional time between clinicians and patients with the goal of increasing knowledge, understanding, and autonomy in pregnant participants. We investigated whether these women would be more likely to receive recommended Tdap and influenza vaccinations relative to others who received one-on-one traditional prenatal care. Our study employed a retrospective chart review of all women who participated in CenteringPregnancy group care compared to a group of matched women who received only traditional prenatal care at a large, quaternary care referral academic center. We extracted demographic and clinical characteristics from charts that included maternal age during pregnancy care and parity. Outcome variables of interest were influenza and Tdap vaccination status. Compared with traditional obstetrical care patients, women who participated in CenteringPregnancy were 1.7-2.7 times more likely to obtain the Tdap and influenza vaccines. These findings may be attributable to the increased opportunity for patient education and social support offered by the CenteringPregnancy model.

Introduction: Childhood immunization schedules often involve multiple vaccinations per visit. When increased risk of an adverse event is observed after simultaneous (same-day) vaccinations, it can be difficult to ascertain which triggered the adverse event. This methods paper discusses a systematic process to determine which of the simultaneously administered vaccine(s) are most likely to have caused an observed increase in risk of an adverse event., Methods: We use an example from the literature where excess risk of seizure was observed 1 day after vaccination, but same-day vaccination patterns made it difficult to discern which vaccine(s) may trigger the adverse event. We illustrate the systematic identification process using a simulation that retained the observed pattern of simultaneous vaccination in an empirical cohort of vaccinated children. We simulated "true" effects for diphtheria-tetanus-acellular pertussis (DTaP) and pneumococcal conjugate (PCV) on risk of seizure the day after vaccination. We varied the independent and interactive effects of vaccines (on the multiplicative scale). After applying the process to simulated data, we evaluated risk of seizure 1 day after vaccination in the empirical cohort., Results: In all simulations, we were able to determine which vaccines contributed to excess risk. In the empirical data, we narrowed the association with seizure from all vaccines in the schedule to three likely candidates, DTaP, PCV, and/or Haemophilus influenzae type B (HiB) (p < 0.01, attributable risk when all three were administered together: five per 100,000). Disentangling their associations with seizure would require a larger sample or more variation in the combinations administered. When none of these three were administered, no excess risk was observed., Conclusion: The process outlined could provide valuable information on the magnitude of potential risk from individual and simultaneousvaccinations. Associations should be further investigated with independent data as well as biologically based, statistically independent hypotheses.

Transplacental antibody transfer from mother to fetus provides protection from infection in the first weeks of life, and the four different subclasses of IgG (IgG1, IgG2, IgG3, and IgG4) have diverse roles in protection against infection. In this study, we evaluated concentrations and transplacental transfer ratios of the IgG subclasses in a healthy UK-based cohort of mother-cord pairs, and investigated associations with maternal, obstetric, and fetal factors. In agreement with previous studies, we found a strong association between maternal and cord IgG for all subclasses. We report a transfer efficiency hierarchy of IgG1>IgG3>IgG4=IgG2 in our study population, and our review of the literature demonstrates that there is no consensus in the hierarchy of subclass transfer, despite the commonly made statement that the order is IgG1>IgG4>IgG3>IgG2. We report additional data regarding negative associations between elevated maternal IgG concentrations and maternal/cord transfer ratios, finding an effect on IgG1, IgG2, and IgG3 subclasses. Levels of IgG subclasses were the same between venous and arterial blood samples from the umbilical cord, but there was a significantly higher level of total IgG in arterial blood. We found no correlation between placental FcRn protein levels and IgG transfer in our cohort, suggesting that IgG is the main determinant of observed differences in transplacental transfer ratios at term. Neonatal IgG1 and IgG4 levels were increased with later gestation at delivery, independent of any increase in transplacental transfer, indicating that the benefit of later gestation is through accumulation of these subclasses in the fetus. Neonatal IgG2 levels and transfer ratios were reduced in rhesus-negative pregnancies, suggesting that administered anti-D antibodies may compete for transplacental transfer of this subclass. Maternal influenza vaccination resulted in elevated maternal and neonatal levels of IgG4, whereas maternal Tdap vaccination had no impact on neonatal levels of the subclasses, nor transfer. However, within Tdap vaccinated pregnancies, later gestation at Tdap vaccination was associated with higher transplacental transfer. Our study provides information regarding levels and transfer of IgG subclasses in healthy term pregnancies and demonstrates the importance of recording detailed clinical information in studies of antibody transfer, including parity, ethnicity, and timing of maternal vaccine delivery., (Copyright © 2020 Clements, Rice, Vamvakas, Barnett, Barnes, Donaldson, Jones, Kampmann and Holder.)

Three vaccines are recommended by the Advisory Committee on Immunization Practices (ACIP) for routine vaccination of adolescents aged 11-12 years to protect against 1) pertussis; 2) meningococcal disease caused by types A, C, W, and Y; and 3) human papillomavirus (HPV)-associated cancers (1). At age 16 years, a booster dose of quadrivalent meningococcal conjugate vaccine (MenACWY) is recommended. Persons aged 16-23 years can receive serogroup B meningococcal vaccine (MenB), if determined to be appropriate through shared clinical decision-making. CDC analyzed data from the 2019 National Immunization Survey-Teen (NIS-Teen) to estimate vaccination coverage among adolescents aged 13-17 years in the United States.* Coverage with ≥1 dose of HPV vaccine increased from 68.1% in 2018 to 71.5% in 2019, and the percentage of adolescents who were up to date † with the HPV vaccination series (HPV UTD) increased from 51.1% in 2018 to 54.2% in 2019. Both HPV vaccination coverage measures improved among females and males. An increase in adolescent coverage with ≥1 dose of MenACWY (from 86.6% in 2018 to 88.9% in 2019) also was observed. Among adolescents aged 17 years, 53.7% received the booster dose of MenACWY in 2019, not statistically different from 50.8% in 2018; 21.8% received ≥1 dose of MenB, a 4.6 percentage point increase from 17.2% in 2018. Among adolescents living at or above the poverty level, § those living outside a metropolitan statistical area (MSA) ¶ had lower coverage with ≥1 dose of MenACWY and with ≥1 HPV vaccine dose, and a lower percentage were HPV UTD, compared with those living in MSA principal cities. In early 2020, the coronavirus disease 2019 (COVID-19) pandemic changed the way health care providers operate and provide routine and essential services. An examination of Vaccines for Children (VFC) provider ordering data showed that vaccine orders for HPV vaccine; tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap); and MenACWY decreased in mid-March when COVID-19 was declared a national emergency (Supplementary Figure 1, https://stacks.cdc.gov/view/cdc/91795). Ensuring that routine immunization services for adolescents are maintained or reinitiated is essential to continuing progress in protecting persons and communities from vaccine-preventable diseases and outbreaks., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Introduction Infants too young to be fully immunized are the most vulnerable to severe pertussis disease. To close this susceptibility gap, passive infant immunization through vaccination of pregnant women against pertussis was first introduced in 2011 in the United States and has been extended since then to more than 40 countries. Areas covered We conducted two systematic literature searches to describe the worldwide burden of pertussis disease in infants <6 months of age since 2005, and the effectiveness and impact of maternal pertussis vaccination in preventing infant pertussis since 2011. Expert opinion Pertussis disease incidence rates in infants aged <2-3 months were substantial in all countries with available data, exceeding 1000 cases per 100,000 population during outbreaks. Virtually all pertussis deaths occurred in this age group. Data from Africa, Eastern Mediterranean, and Asia were limited, but suggest a similar or higher disease burden than in Europe or the Americas. Estimates of effectiveness of second/third trimester pertussis vaccination in preventing pertussis disease in <2-3 months old infants were consistently high (69%-93%) across the observational studies reviewed, conducted in various settings with different designs. Maternal vaccination programs appear to be achieving their goal of reducing the burden of disease in very young infants. Plain language summary What is the context? Pertussis, also known as whooping cough, is a highly contagious disease of the respiratory tract. Infants too young to be fully vaccinated are at the highest risk of severe pertussis disease, hospitalization, and death. Vaccinating pregnant women against pertussis with a Tdap vaccine is recommended in more than 40 countries as a safe and effective strategy to protect infants for the first months of life. What is new? This review summarizes recent literature describing the burden of pertussis disease in infants worldwide prior to the introduction of maternal vaccination programs; pertussis disease incidence rates in infants aged <2-3 months were substantial in all countries with available data, exceeding 1000 cases per 100,000 population during outbreaks. Immunization of pregnant women with a Tdap vaccine can prevent about 70-90% of pertussis disease and up to 90.5% of pertussis hospitalizations in infants under 3 months of age. What is the impact? Limited available data suggest that incidence rates of pertussis disease after the introduction of Tdap maternal immunization have declined in infants. Current knowledge supports the implementation of Tdap maternal immunization programs.