Search

BACKGROUND: This report summarizes the discussions and conclusions from the Correlates of Protection for Next Generation Influenza Vaccines: Lessons Learned from the COVID-19 Pandemic meeting, which took place in Seattle, USA, from March 1, 2023, to March 3, 2023. CONCLUSIONS: Discussions around influenza virus correlates of protection and their use continued from where the discussion had been left off in 2019. While there was not much progress in the influenza field itself, many lessons learned during the coronavirus disease 2019 (COVID-19) pandemic, especially the importance of mucosal immunity, were discussed and can directly be applied to influenza correlates of protection.

BACKGROUND: The effect of vaccination on the epigenome remains poorly characterized. In previous research, we identified an association between seroprotection against influenza and DNA methylation at sites associated with the RIG-1 signaling pathway, which recognizes viral double-stranded RNA and leads to a type I interferon response. However, these studies did not fully account for confounding factors including age, gender, and BMI, along with changes in cell-type composition. RESULTS: Here, we studied the influenza vaccine response in a longitudinal cohort vaccinated over two consecutive years (2019-2020 and 2020-2021), using peripheral blood mononuclear cells and a targeted DNA methylation approach. To address the effects of multiple factors on the epigenome, we designed a multivariate multiple regression model that included seroprotection levels as quantified by the hemagglutination-inhibition (HAI) assay test. CONCLUSIONS: Our findings indicate that 179 methylation sites can be combined as potential signatures to predict seroprotection. These sites were not only enriched for genes involved in the regulation of the RIG-I signaling pathway, as found previously, but also enriched for other genes associated with innate immunity to viruses and the transcription factor binding sites of BRD4, which is known to impact T cell memory. We propose a model to suggest that the RIG-I pathway and BRD4 could potentially be modulated to improve immunization strategies.

The aim of this project was to increase willingness to receive the influenza vaccine to the optimal rate of ≥ 70%. Low acuity adult patients who visited an Emergency Department (ED) were assessed regarding their willingness to receive the influenza vaccine before and after an educational intervention that included a provider recommendation and an educational handout. A total of seventy-six patients (n = 76) were assessed. Patients willingness to receive the influenza vaccine rose from 29% pre-intervention to 72% post-intervention without disrupting the clinical flow in a busy ED. Similar vaccine educational strategies can be applied to influenza and other vaccines in EDs  to increase vaccination willingness in patients, including those who use the ED as a primary point of contact for healthcare, decreasing the burden of influenza illness in the community.

Explore pediatric staff experiences administering the second influenza vaccine dose. Qualitative focus groups/interviews. As part of the National Institutes of Health-funded Flu2Text randomized control trial of text message reminders for second influenza vaccine dose, we conducted seven focus groups and four individual interviews (n = 39 participants total) with clinicians and staff from participating practices from the American Academy of Pediatrics' Pediatric Research in Office Settings (PROS) Network. Of 37 participating practices, 10 were selected through stratified sampling of practices with highest (n = 5) and lowest (n = 5) randomized controlled trial effect sizes. A semi-structured discussion guide included questions that addressed parental, practice, and health system barriers/facilitators to second influenza vaccine dose administration. Using the Systems Model of Clinical Preventive Care as a conceptual framework, two investigators independently coded transcripts (Κ = 0.86, high agreement) with NVivo 12 Plus. Coding inconsistencies were resolved by consensus. Clinicians/staff reported that administering the second influenza vaccine dose in a season was more complex than other childhood vaccines. They highlighted parental uncertainty about the need for the second dose and the difficulty and inconvenience of bringing children back to the office as important barriers. Caregiver–staff relationships were perceived as helpful in getting children vaccinated with their second dose and vaccine reminders were seen as important cues-to-action. Ensuring receipt of two doses of the influenza vaccine in a given season presents unique challenges. Themes identified provide a framework for understanding opportunities to bolster second dose receipt, including explaining why two doses are needed, offering flexible hours for vaccination, and sending vaccine reminders. [ABSTRACT FROM AUTHOR]

Background: Adults 65 years of age and older are at higher risk of influenza complications, such as hospitalization and death. As a result, seasonal influenza immunization is particularly important for this group. Objective: This supplemental statement provides an evidence summary on the preferential use of one or more of the age-appropriate influenza vaccines for adults 65 years of age and older, over other age-appropriate influenza vaccines. Methods: The National Advisory Committee on Immunization (NACI)’s Influenza Working Group undertook an overview of existing systematic reviews on the efficacy, effectiveness, safety and cost effectiveness of influenza vaccination in adults 65 years of age and older. Additionally, NACI’s evidence-based process was used to assess the quality of eligible studies, summarize and analyze the findings and apply an ethics, feasibility and acceptability lens to develop recommendations. Results: The evidence suggests that high-dose inactivated influenza vaccine (IIV-HD), adjuvanted inactivated influenza vaccine (IIV-Adj) and recombinant influenza vaccine (RIV) offer increased benefits for adults 65 years of age and older when compared to standard dose influenza vaccines. The IIV-HD had the most supporting evidence, followed by IIV-Adj and then RIV. Evidence comparing these enhanced vaccines was limited. Conclusion: Following a thorough review of the complete body of evidence, NACI recommends that IIV-HD, IIV-Adj or RIV should be offered over other influenza vaccines for adults 65 years of age and older. NACI also continues to strongly recommend the inclusion of adults 65 years of age and older among those for whom it is particularly important to receive influenza vaccination. [ABSTRACT FROM AUTHOR]

Background: The National Advisory Committee on Immunization (NACI) reviews the evolving evidence on influenza immunization and provides annual recommendations regarding the use of seasonal influenza vaccines. The NACI Statement on Seasonal Influenza Vaccine for 2024– 2025 updates the NACI recommendations from the previous year. Objective: To summarize the 2024–2025 NACI seasonal influenza vaccine recommendations and to highlight new and updated information. Methods: For the development of the Statement on Seasonal Influenza Vaccine for 2024–2025, the NACI Influenza Working Group applied the NACI evidence-based process to assess available evidence and formulate recommendations. These recommendations underwent a thorough evaluation and were approved by NACI based on the available evidence. Results: Key updates for the 2024–2025 influenza season include updated immunization recommendations reflecting changes in influenza epidemiology and revised guidance for vaccine administration during pregnancy and in older adults. Conclusion: The National Advisory Committee on Immunization recommends that any age-appropriate quadrivalent or trivalent influenza vaccine should be used for individuals six months of age and older who do not have contraindications or precautions. NACI reaffirms the importance of influenza vaccination with inactivated or recombinant influenza vaccines in pregnancy. Finally, NACI recommends that inactivated high-dose (IIV-HD), inactivated adjuvanted (IIV-Adj) or recombinant influenza vaccine (RIV) should be offered, when available, over other influenza vaccines for adults 65 years of age and older. [ABSTRACT FROM AUTHOR]

Natural adjuvants have recently garnered interest in the field of vaccinology as their immunostimulatory effects. In this study, we aimed to investigate the potential use of Peyssonnelia caulifera (PC), a marine alga, as a natural adjuvant for an inactivated split A/Puerto Rico/8/1934 H1N1 influenza vaccine (sPR8) in a murine model. We administered PC-adjuvanted vaccines to a murine model via intramuscular prime and boost vaccinations, and subsequently analyzed the induced immunological responses, particularly the production of antigen-specific IgG1 and IgG2a antibodies, memory T and B cell responses, and the protective efficacy against a lethal viral infection. PC extract significantly bolstered the vaccine efficacy, demonstrating balanced Th1/Th2 responses, increased memory T and B cell activities, and improved protection against viral infection. Notably, within 3 days post-vaccination, the PC adjuvant stimulated activation markers on dendritic cells (DCs) and macrophages at the inguinal lymph nodes (ILN), emphasizing its immunostimulatory capabilities. Furthermore, the safety profile of PC was confirmed, showing minimal local inflammation and no significant adverse effects post-vaccination. These findings contribute to our understanding of the immunomodulatory properties of natural adjuvants and suggest the promising roles of natural adjuvants in the development of more effective vaccines for infectious diseases. [ABSTRACT FROM AUTHOR]

This manuscript offers an in-depth comparative examination of the effectiveness of higher-dose (double standard-dose and high-dose) influenza vaccines in contrast to a single standard-dose vaccine when it comes to alleviating major cardiovascular events. Meta-Analysis. To conduct this study, an exhaustive search was carried out in the medical English literature using databases such as PubMed/MEDLINE, EMBASE, and the Cochrane CENTRAL until 10 April 2024. The evaluation of associations was achieved through the calculation of pooled relative risks (RRs) accompanied by their corresponding 95% confidence intervals (CIs). A meticulous analysis encompassed a comprehensive cohort of 68,713 patients. Among these participants, 34,430 individuals were randomly assigned to receive a higher-dose influenza vaccination, whereas 34,283 received the standard influenza vaccination. Contrary to initial expectations, a higher-dose influenza vaccine did not manifest elevated efficacy compared to the standard-dose vaccine in terms of mitigating major cardiovascular events. The computed pooled RR stood at 1.0, accompanied by a 95% CI ranging from 0.93 to 1.10. While this systematic review and meta-analysis did not find a statistically significant advantage of higher-dose influenza vaccines over a single standard-dose vaccine in preventing major cardiovascular events, the observed trend towards risk reduction warrants continued investigation. These findings contribute to the ongoing dialogue surrounding vaccination strategies and their implications for cardiovascular outcomes. [ABSTRACT FROM AUTHOR]

Background: Concomitant administration of COVID-19, influenza, and pneumococcal vaccines could reduce the burden on healthcare systems. However, the immunogenicity and safety of various combinations of a third booster dose of SARS-CoV-2 inactivated vaccine (CoronaVac), inactivated quadrivalent influenza vaccine (IIV4), and 23-valent pneumococcal polysaccharide vaccine (PPV23), particularly in different age groups, is still unknown. Methods: A phase 4, randomized, open-label, controlled trial was conducted in Beijing, China. 636 healthy adults were divided into two age groups (18-59 and ≥60 years) and randomized equally into three groups: CoronaVac and IIV4 followed by PPV23; CoronaVac and PPV23 followed by IIV4; or CoronaVac followed by IIV4 and PPV23, with a 28-day interval between vaccinations. Immunogenicity was evaluated by measuring antibody titers, and safety was monitored. ClinicalTrials.gov Identifier: NCT05298800. Results: Co-administration of a third dose of CoronaVac, IIV4, and PPV23 in any combination was safe. Among adults aged 18-59, co-administration with PPV23 maintained non-inferiority of antibody levels for CoronaVac and IIV4, despite a slight reduction in antibody responses. This reduction was not observed in participants ≥60 years. Furthermore, co-administration of IIV4 and PPV23 affected seroconversion rates for both vaccines. Conclusions: Co-administration of the third dose of SARS-CoV-2 inactivated vaccine with the influenza vaccine, followed by PPV23, may be optimal for adults aged 18-59. In adults ≥60, all vaccine combinations were immunogenic, suggesting a flexible vaccination approach. Since antibody measurements were taken 28 days post-vaccination, ongoing surveillance is essential to assess the longevity of the immune responses. [ABSTRACT FROM AUTHOR]

Objective To understand the influenza vaccination status of permanent residents in Macao and analyze the influencing factors. Methods A stratified cluster sampling method was employed to conduct a questionnaire survey of permanent residents in Macao from November 16 to 22, 2020. The survey primarily included basic knowledge of influenza, individual vaccination behavior, and vaccination status of family members. Chi-square tests and univariate and multivariate logistic regression models were utilized to explore the factors influencing public vaccination against influenza. Results A total of 2 207 residents participated in the survey, with males accounting for 45.3% and females accounting for 54.7%. In total, 62.1% of respondents reported having received the influenza vaccine in the past 12 months, and 61.0% of respondents exhibited a low level of knowledge regarding influenza. Multivariate logistic regression analysis indicated that the likelihood of receiving the influenza vaccine was higher among older individuals (aged over 50, OR=3.064, 95%CI: 1.114-7.814), those with fewer family members (1-2 members, OR=1.752, 95%CI: 1.323-2.320), those with a moderate monthly household income (40 000-60 000 yuan, OR=1.126, 95%CI: 1.852-1.489), individuals with higher educational attainment (higher education, OR=1.167, 95%CI: 1.949-1.434), those in high-risk professions (healthcare workers compared to civil servants, OR=2.730, 95%CI: 1.700-4.383), individuals in poorer health who were not pregnant (healthy individuals compared to pregnant patients, OR=2.060, 95%CI: 1.634-1.772; chronic disease patients, OR=2.623, 95%CI: 1.948-2.779), and those with a higher level of vaccine knowledge (OR=1.531, 95%CI: 1.069-2.194). Conclusion The influenza vaccination rate in Macao is relatively high on a global scale. However, there is still a need to strengthen educational outreach regarding influenza vaccination, encourage residents to get vaccinated, and actively promote collective vaccination activities in schools and institutions to fully utilize the role of community immunity. [ABSTRACT FROM AUTHOR]

The MDCK cell line is perceived as better than the embryos of hen eggs for the production of influenza vaccines, but the tumorigenicity of these cells is concerning. Epidermal growth factor receptor (EGFR) is likely to be a crucial target that contributes to the tumorigenicity of MDCK cells. In this study, EGFR-knockdown and EGFR-overexpression cell lines were established. EGFR's influence on cell growth, migration, clonogenic ability, and flu virus susceptibility was evaluated in vitro, and its role in cell tumorigenicity was examined in nude mice. GST pull-down coupled with mass spectrometry (MS) and bioinformatics analysis identified EGFR-interacting proteins. The expression levels of these proteins, as well as those of PI3K–AKT- and MAPK–ERK-signaling-pathway-related molecules, were confirmed at both gene and protein levels. The result indicates that EGFR overexpression can enhance cell proliferation, migration, and clonal formation; EGFR knockdown could effectively curtail tumorigenesis and amplify the titers of influenza viruses in MDCK cells. An analysis of the underlying mechanism identified a total of 21 interacting proteins implicated in tumor formation, and among these, AKT1, CDK4, GNB2, and MAPK8 were confirmed at both gene and protein levels. EGFR can activate key factors of the PI3K–AKT signaling pathway, AKT and PI3K, and promote their phosphorylation levels. Consequently, we concluded that EGFR interacts with GNB2, facilitating transmembrane signal transduction, activating the PI3K–AKT signaling cascade, controlling cell cycle alterations, stimulating cell proliferation, and promoting tumorigenesis. [ABSTRACT FROM AUTHOR]

Background: In 2022, publicly funded influenza vaccine was made available to all residents of Queensland, Australia. This study compared influenza epidemiology in 2022 with previous years (2017–2021) and estimated influenza vaccine effectiveness (VE) during 2022. Methods: The study involved a descriptive analysis of influenza notifications and a case–control study to estimate VE. Cases were notifications of laboratory‐confirmed influenza, and controls were individuals who were test negative for COVID‐19. Cases and controls were matched on age, postcode and specimen collection date. VE against hospitalisation was investigated by matching hospitalised cases to controls. Conditional logistic regression models were adjusted for sex. Results: In 2022, Queensland experienced an early influenza season onset (April–May) and high case numbers (n = 45,311), compared to the previous 5 years (annual average: 29,364) and 2020–2021 (2020:6047; 2021:301) during the COVID‐19 pandemic. Adjusted VE (VEadj) against laboratory‐confirmed influenza was 39% (95% confidence interval [CI]: 37–41), highest for children aged 30 months to < 5 years (61%, 95% CI: 49–70) and lowest for adults aged ≥ 65 years (24%, 95% CI: 17–30). VEadj against influenza‐associated hospitalisation was 54% (95% CI: 48–59). Among children < 9 years of age, VEadj against laboratory‐confirmed influenza (55%, 95% CI: 49–61) and hospitalisation (67%, 95% CI: 39–82) was higher in those who received a complete dose schedule. Conclusion: In Queensland, the 2022 influenza season started earlier than the previous 5 years. VE against influenza notifications varied across age groups. VE estimates against influenza‐associated hospitalisation were higher than those against laboratory‐confirmed influenza. [ABSTRACT FROM AUTHOR]

Seasonal influenza vaccine effectiveness is low. Carbohydrate fatty acid monosulphate ester (CMS), a new oil-in-water adjuvant, has proven potency in animal models with suggested capacity for dose-sparing. The objective was to evaluate safety and immunogenicity of CMS when added to a low-dose influenza vaccine (QIV) in humans. In a randomised, double-blind, active-controlled, first-in-human study, sixty participants (18–50 years) received either 0.5 mg CMS or 2 mg CMS with 1/5th dose QIV, or a full dose QIV without CMS. Adverse events (AE) were monitored until 7 days post-vaccination. Haemagglutinin inhibition (HI) titres in serum and CD4+ T cells in PBMCs were determined at day 0, 7, 28, and 180. Mean age was 37.6 (±10.1) years and 42/60 (70.0%) were female. Pain at injection site (42/60, 86.7%) and headache (34/60, 56.7%) were reported most and more frequently in the 2 mg CMS group. HI titres and the frequency of influenza specific CD4+ T cells were equal across strains for the three cohorts on all visits, increased until day 28 and decreased at day 180 to values higher than baseline. CMS was safe in humans. Humoral and cell-mediated immunogenicity was similar across vaccines, even with 1/5th antigen dose. CMS can have beneficial implications in low-resource settings or in a pandemic context. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine the safety, tolerability and immunogenicity of TetraFluBet, an inactivated subunit influenza vaccine that contains a corpuscular immuno-adjuvant derived from natural betulin. Methods: We conducted a prospective, randomized, open-labeled, single-center, phase I trial. The study was conducted in two stages: 5 volunteers in stage I and 25 volunteers in stage II. Eligible participants received one single dose (20 μg/0.5 mL) of TetraFluBet intramuscularly. Participants were followed for adverse events and reactogenicity. Seroconversion rate, seroprotection level, geometric mean titers (GMTs) of virus-neutralizing antibodies, IFN-γ induction and cell-mediated immunity were assessed. Results: A total of 30 participants were enrolled. No vaccine-related serious adverse events were observed. The proportions of study participants with 4-fold seroconversions assessed by the HI assay (with 95% CIs) were 80.0% (62.7; 90.5), 70.0% (52.1; 83.3), 63.3% (45.5; 78.1) and 73.3% (55.6; 85.8) for influenza virus subtypes A (H1N1), A (H3N2), B1 and B2, respectively. Seroprotection levels (with 95% CIs) were 83.3% (66.4; 92.7), 83.3% (66.4; 92.7), 73.3% (55.6; 85.8) and 66.7% (48.8; 80.8), respectively. The fold increases in the GMTs of virus-neutralizing antibodies for subtype H1N1 was 6.50, for subtype H3N2 was 3.03, for subtype B1 was 3.56 and for subtype B2 was 6.07. The population of cytotoxic T-cells increased significantly in the post-vaccination period, indicating a strong CD3+CD8+ response. Conclusions: TetraFluBet tetravalent inactivated subunit vaccine with adjuvant demonstrated pronounced immunogenic properties, leading to the formation of both specific humoral and cellular immunity at a 20 μg dose. [ABSTRACT FROM AUTHOR]

Maternal vaccination is a safe and effective means of preventing infection in pregnant women, their fetuses, and infants after birth. Several vaccines are routinely administered in pregnancy as a valuable part of prenatal care with supporting recommendations from national and international health organizations. Fears concerning vaccine safety in pregnancy are pervasive despite sufficient available safety data to support their use, leading to underutilization of maternal immunization. Despite this hesitancy, the field of maternal vaccination is evolving to include more vaccines in the routine prenatal vaccination schedule, including the new RSV vaccine. This review discusses the currently recommended vaccines in pregnancy, evidence for their use, and an overview of ongoing clinical trials investigating prospective vaccines for pregnant women. [ABSTRACT FROM AUTHOR]

Background.In the absence of a vaccine against SARS-CoV-2, seasonal influenza vaccination during the pandemic contributed to lowered COVID-19 susceptibility and severity. The study was aimed to assess the state of post-influenza vaccination immunity, pneumonia frequency and severity in medical workers after using various flu vaccination regimens, between the 1st and 2nd peaks of COVID-19 epidemic rise.Materials and methods.Comparatively analyzed data on the levels of antibodies against influenza virus strains and pneumonia incidence in 487 medical workers was carried out: 1st group — unvaccinated in 2020–2021 (n = 281), 2nd group — vaccinated against influenza (Sovigripp), (n = 98), 3rd group — received combined vaccination against influenza and pneumococcus (Prevenar 13), (n = 108).Results.6 months after vaccination, the highest rates of influenza virus were detected in the A(H3N2), the level of seroprotection (≥ 1:40) ranged from 49.0% in unvaccinated (1st group) to 53.4–53.2% in those who received combined vaccination (group III), as well as influenza alone (2nd group), p 0.05; for strain A(H1N1) the level of seroprotection in 1st group is 24.5%, lower (p 0.04) than in 2nd group — 32.7%, but does not differ from the levels of 40.4% in group III; for strain B the level of seroprotection is the lowest ranging from 19.4% in the group of unvaccinated subjects up to 22.4% in 2nd group and 23.4% in 3rd group. The pneumonia incidence in 1st group (3.9%), 2nd group (3.1%), 3rd group (4.6%) did not differ, however, among all vaccinated subjects severity of pneumonia clinical course was mild, whereas in unvaccinated employees, except for mild course (45.4%, 5 out of 11 people) pneumonia in 36.4% (4 out of 11 people) cases was assessed as moderate and in 18.2% (2 out of 11 people) cases — severe with fatal outcomes.Conclusion.The study showed that 6 months after seasonal influenza immunization between the 1st and 2nd peaks of COVID-19 epidemic rise, the immunogenicity of the vaccine meets the CPMP criterion for the A(H3N2) strain. In vaccinated patients, the proportion of pneumonia with COVID-19 clinical picture was mild in 100% of cases, and in unvaccinated patients in 36.4% of cases — of moderate severity and in 18.2% — severe with fatal outcome.

Abstract Natural adjuvants have recently garnered interest in the field of vaccinology as their immunostimulatory effects. In this study, we aimed to investigate the potential use of Peyssonnelia caulifera (PC), a marine alga, as a natural adjuvant for an inactivated split A/Puerto Rico/8/1934 H1N1 influenza vaccine (sPR8) in a murine model. We administered PC-adjuvanted vaccines to a murine model via intramuscular prime and boost vaccinations, and subsequently analyzed the induced immunological responses, particularly the production of antigen-specific IgG1 and IgG2a antibodies, memory T and B cell responses, and the protective efficacy against a lethal viral infection. PC extract significantly bolstered the vaccine efficacy, demonstrating balanced Th1/Th2 responses, increased memory T and B cell activities, and improved protection against viral infection. Notably, within 3 days post-vaccination, the PC adjuvant stimulated activation markers on dendritic cells (DCs) and macrophages at the inguinal lymph nodes (ILN), emphasizing its immunostimulatory capabilities. Furthermore, the safety profile of PC was confirmed, showing minimal local inflammation and no significant adverse effects post-vaccination. These findings contribute to our understanding of the immunomodulatory properties of natural adjuvants and suggest the promising roles of natural adjuvants in the development of more effective vaccines for infectious diseases.

ABSTRACTBackground Clinical evidence supports use of enhanced influenza vaccines in older adults. Few economic outcome studies have compared adjuvanted trivalent inactivated (aIIV3) and standard egg-derived quadrivalent inactivated influenza vaccines (IIV4e).Research Design and Methods A retrospective cohort study was conducted leveraging deidentified US hospital data linked to claims data during the 2018–19 and 2019–20 influenza seasons. Relative vaccine effectiveness (rVE) was compared in adults aged ≥ 65 years receiving aIIV3 or IIV4e using inverse probability of treatment weighting (IPTW) and Poisson regression. An economic assessment quantified potential real-world cost savings.Results The study included 715,807 aIIV3 and 320,991 IIV4e recipients in the 2018–19 and 844,169 aIIV3 and 306,270 IIV4e recipients in the 2019–20 influenza seasons. aIIV3 was significantly more effective than IIV4e in preventing cardiorespiratory disease (2018–19 rVE = 6.2%; and 2019–20 rVE = 6.0%) and respiratory disease (2018–19 rVE = 8.9%; and 2019–20 rVE = 10.1%). During the 2018–19 influenza season cardiorespiratory hospitalization cost savings for the aIIV3 population were $392 M, and $221 M for the 2019–20 season. Respiratory hospitalization cost savings for the aIIV3 population were $145 M and $97 M, respectively.Conclusions Our findings suggest that aIIV3 provides clinical and economic advantages versus IIV4e in the elderly.

ABSTRACTBackground Cell-based quadrivalent influenza vaccines (QIVc) can increase effectiveness against seasonal influenza by avoiding mismatch from egg adaption of vaccine viruses. This study evaluates the population-level cost-effectiveness and impacts on health outcomes of QIVc versus an egg-based vaccine (QIVe) in children aged 6 months to 17 years in the US.Research Design and Methods A dynamic age-structured susceptible-exposed-infected-recovered model was used to simulate influenza transmission in low and high incidence seasons for two scenarios: 1. QIVe for 6 months–17 year-olds, QIVc for 18–64 year-olds, and adjuvanted QIV (aQIV) for ≥ 65 year-olds, and 2. QIVc for 6 months–64 year-olds, and aQIV for ≥ 65 year-olds. Probabilistic sensitivity analysis was performed to account for uncertainty in parameter estimates. Cost-effectiveness was evaluated as incremental cost-effectiveness ratios (ICERs).Results Extension of QIVc to children resulted in 3–4% reductions in cases (1,656,271), hospitalizations (16,688), and deaths (2,126) at a population level in a high incidence season, and 65% reductions (cases: 2,856,384; hospitalizations: 31667; deaths: 4,163) in a low incidence season. Use of QIVc would be cost-saving, with ICERs of -$16,427/QALY and -$8,100/QALY from a payer perspective and -$22,669/QALY and -$15,015/QALY from a societal perspective, for low and high incidence seasons respectively. Cost savings were estimated at approximately $468 million and $1.366 billion for high and low incidence seasons, respectively.Conclusion Use of QIVc instead of QIVe in children > 6 months of age in the US would reduce the disease burden and be cost-saving from both a payer and societal perspective.

ABSTRACTBackground Delays in influenza vaccine delivery and administration can hinder vaccine coverage and protection. This study examines the differentials in distributing and administering adjuvanted trivalent (aTIV) and quadrivalent influenza vaccines (aQIV) to older adults in Italy’s primary care setting and its potential impact on hospitalization risk over 5 epidemic seasons.Methods Using a primary care database, individuals aged ≥ 65 years were selected. The proportion of vaccine distribution to regional authorities and subsequent administration by GPs was estimated using census data. Using quantile (median) regression, we examined the relationship between velocities of vaccine distribution and administration (doses/week) and the incidence of hospitalizations.Results Over the 5 influenza seasons, the velocity of distribution and administration of aTIV/aQIV ranged 341–833 and 152–270 median doses/week; no trend was yielded for the difference between these velocities (p = 0.189) or vaccine coverage (p = 0.142). An association was observed for each differential dose/week between distributed and administered vaccines and all-cause hospitalizations with a 10% increase in 2017–2018, 54% in 2018–2019, and 12% in 2020–2021 season.Conclusions These findings highlight the importance of minimizing the time lapse between vaccine distribution and administration to mitigate the impact of influenza and address factors that contribute to vaccination barriers.

Maternal vaccination is a safe and effective means of preventing infection in pregnant women, their fetuses, and infants after birth. Several vaccines are routinely administered in pregnancy as a valuable part of prenatal care with supporting recommendations from national and international health organizations. Fears concerning vaccine safety in pregnancy are pervasive despite sufficient available safety data to support their use, leading to underutilization of maternal immunization. Despite this hesitancy, the field of maternal vaccination is evolving to include more vaccines in the routine prenatal vaccination schedule, including the new RSV vaccine. This review discusses the currently recommended vaccines in pregnancy, evidence for their use, and an overview of ongoing clinical trials investigating prospective vaccines for pregnant women.

Abstract Background The effect of vaccination on the epigenome remains poorly characterized. In previous research, we identified an association between seroprotection against influenza and DNA methylation at sites associated with the RIG-1 signaling pathway, which recognizes viral double-stranded RNA and leads to a type I interferon response. However, these studies did not fully account for confounding factors including age, gender, and BMI, along with changes in cell-type composition. Results Here, we studied the influenza vaccine response in a longitudinal cohort vaccinated over two consecutive years (2019–2020 and 2020–2021), using peripheral blood mononuclear cells and a targeted DNA methylation approach. To address the effects of multiple factors on the epigenome, we designed a multivariate multiple regression model that included seroprotection levels as quantified by the hemagglutination-inhibition (HAI) assay test. Conclusions Our findings indicate that 179 methylation sites can be combined as potential signatures to predict seroprotection. These sites were not only enriched for genes involved in the regulation of the RIG-I signaling pathway, as found previously, but also enriched for other genes associated with innate immunity to viruses and the transcription factor binding sites of BRD4, which is known to impact T cell memory. We propose a model to suggest that the RIG-I pathway and BRD4 could potentially be modulated to improve immunization strategies.

Background: Annual influenza vaccination is crucially recommended for the elderly to maintain humoral immunity. Insufficient coverage requires us to understand the determinants of their influenza behaviors and how these patterns impact vaccination choices. Methods: Data from 540 Beijing residents aged over 65 were collected through interviews, capturing vaccination history and sociodemographic details. Individual influenza vaccination records from 2016 to 2020 were obtained from China’s Immunization Information Systems. A latent class model identified three vaccination patterns. Multinomial logistic regression assessed relative risk ratios (RRRs) for vaccination based on sociodemographic factors. Vaccination patterns were used to predict future vaccination likelihood. Results: The analysis revealed three groups: sporadically vaccinated (63.33%), occasionally vaccinated (18.71%), and frequently vaccinated (17.96%). Factors associated with frequent vaccination included age over 70 (RRR = 2.81), lower income (RRR = 0.39), higher vaccine hesitancy (RRR = 3.10), multiple chronic conditions (RRR = 2.72), and rural residence (RRR = 2.48). The frequently vaccinated group was more likely to sustain regular vaccination habits in subsequent years compared to the occasionally vaccinated group. Conclusions: Only 17.96% of Beijing’s older population exhibited a consistent influenza vaccination pattern. Older age, rural residency, and chronic diseases correlated with repeated influenza vaccination. Segmenting the population based on past vaccination behavior can aid in designing targeted interventions to improve vaccination rates.

Abstract Aims Takotsubo syndrome (TTS) is a rare complication of vaccination. In this study, we sought to provide insight into the characteristics of reported TTS induced by vaccination. Methods and results We did a systematic review, searching PubMed, Embase, Web of Science, Ovid MEDLINE, Journals@Ovid, and Scopus databases up to 26 April 2023 to identify case reports or case series of vaccine‐induced TTS. We then extracted and summarized the data from these reports. Eighteen reports were identified, with a total of 19 patients with TTS associated with vaccinations. Of the 19 included patients, the majority were female (n = 13, 68.4%) with a mean age of 56.6 ± 21.9 years. Seventeen patients developed TTS after coronavirus disease 2019 vaccination, 14 of whom received an mRNA vaccination. Two cases of TTS occurred after influenza vaccination. Among the 19 patients, 17 (89.5%) completed transthoracic echocardiography and 16 (84.2%) underwent angiography procedures. Seven patients (36.8%) completed cardiac magnetic resonance imaging. The median time to symptom onset was 2 (inter‐quartile range, 1–4) days. The most common symptoms were chest pain (68.4%), dyspnoea (57.9%), and digestive symptoms (31.6%). A total of 57.9% of patients developed nonspecific symptoms such as fatigue, myalgia, diaphoresis, and fever. Among the 16 reported cases of TTS, 15 patients (93.8%) exhibited elevated cardiac troponin levels, while among the nine reported cases, eight patients (88.9%) had elevated natriuretic peptide levels. All patients had electrocardiographic changes: ST‐segment change (47.1%), T‐wave inversion (58.8%), and prolonged corrected QT interval (35.3%). The most common TTS type was apical ballooning (88.2%). Treatment during hospitalization typically included beta‐blockers (44.4%), angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers (33.3%), and diuretics (22.2%). After treatment, 81.3% of patients were discharged with improved symptoms. Among this group, nine patients (56.3%) were reported to have recovered ventricular wall motion during follow‐up. Two patients (12.5%) died following vaccination without resuscitation attempts. Conclusions TTS is a rare but potentially life‐threatening complication of vaccination. Typical TTS symptoms such as chest pain and dyspnoea should be considered alarming symptoms, though nonspecific symptoms are common. The risks of such rare adverse events should be balanced against the risks of infection.

B cell receptors (BCRs) play a crucial role in recognizing and fighting foreign antigens. High-throughput sequencing enables in-depth sampling of the BCRs repertoire after immunization. However, only a minor fraction of BCRs actively participate in any given infection. To what extent can we accurately identify antigen-specific sequences directly from BCRs repertoires? We present a computational method grounded on sequence similarity, aimed at identifying statistically significant responsive BCRs. This method leverages well-known characteristics of affinity maturation and expected diversity. We validate its effectiveness using longitudinally sampled human immune repertoire data following influenza vaccination and SARS-CoV-2 infections. We show that different lineages converge to the same responding Complementarity Determining Region 3, demonstrating convergent selection within an individual. The outcomes of this method hold promise for application in vaccine development, personalized medicine, and antibody-derived therapeutics. [ABSTRACT FROM AUTHOR]

Objectives: The present study aimed to assess influenza vaccine hesitancy and vaccine literacy levels among youth and adults in China, as well as the association between them. Methods: An online cross-sectional survey was conducted in Mainland China. Participants' total vaccine literacy and three sub-dimension vaccine literacy (knowledge literacy, competence literacy, and decision-making literacy) were assessed by a validated vaccine literacy scale. Having received influenza vaccination in the past three years or intending to accept it in next influenza season indicates less influenza vaccine hesitancy. Results: Among 997 participants, a sub-optimal vaccine literacy was observed, with a mean score of 66.83 ± 10.27. Regression models 1-4 revealed that participants with middle (aOR: 1.431, P=0.039, 95% CI: 1.018~2.010) or high (aOR: 1.651, P=0.006, 95% CI: 1.157~2.354) total vaccine literacy, as well as those with high competence literacy (aOR: 1.533, P=0.017, 95% CI: 1.079~2.180), or high decision-making literacy (aOR: 1.822, P=0.001, 95% CI: 1.261~2.632) were more likely to have been vaccinated against influenza at least once in past three years. However, those with a high knowledge literacy were associated with a lower influenza vaccine rate (aOR: 0.676, P=0.046, 95% CI: 0.460~0.994). Regression models 5-8 revealed that participants with middle (aOR: 1.661, P=0.008, 95% CI: 1.142~2.414) or high total vaccine literacy (aOR: 2.645, P=0.000, 95% CI: 1.774~3.942), as well as those with middle (aOR: 1.703, P=0.005, 95% CI: 1.177~2.464) or high competence literacy (aOR: 2.346, P=0.000, 95% CI: 1.159~3.461), or high decision-making literacy (aOR: 2.294, P=0.000, 95% CI: 1.531~3.436) were more likely to express the willingness to receive the influenza vaccine in the next influenza season. Conclusion: The participants' influenza vaccine hesitancy was negatively associated with their total vaccine literacy levels and two of the three subdimensions: competence literacy and decision-making literacy. Knowledge literacy suggested a positive or no relationship with influenza vaccine hesitancy. [ABSTRACT FROM AUTHOR]

Influenza vaccination is the main method of preventing influenza. Vaccination is recommended for certain individuals with diseases that could cause complications in the case of flu infection. The objective of this retrospective observational study was to examine influenza vaccination coverage in patients with risk factors, to describe the characteristics of those vaccinated and to study the influence of COVID-19. The study population was children under 14 years old with risk factors between 2018/19 and 2022/23 in Central Catalonia, sourced through the electronic database of the Catalan Institute of Health. The association of influenza vaccination data with sociodemographic data and risk factors was performed by bivariate and multivariate analysis. A total of 13,137 children were studied. Of those, 4623 had received the influenza vaccine in at least one season. The average influenza vaccination rate was 28.8%. The statistically significant factors associated with vaccination were age and having certain risk factors: asthma, diabetes, haemoglobinopathies and clotting disorders. In all seasons, the immigrant population was vaccinated more than the native population p < 0.05, except for the COVID-19 season (2020/21), where no differences were observed. Of those vaccinated, 7.1% had been vaccinated for 5 consecutive years. Influenza vaccination coverage in the paediatric age group was low. Vaccination promotion measures must be implemented. COVID-19 meant an increase in vaccination of the native population to the same level as that of the immigrant population. [ABSTRACT FROM AUTHOR]

While most countries provide safe and effective influenza vaccines for at-risk groups, influenza vaccine coverage among children with rheumatic diseases remains uncertain. This study investigated influenza vaccination rates in children with juvenile idiopathic arthritis (JIA) during the 2019–2020 season and assessed the knowledge and attitudes of caregivers of children with JIA regarding influenza vaccination. The secondary aims were to identify barriers to vaccination and explore strategies to improve vaccination rates. A multi-centre, cross-sectional anonymous survey was conducted in 7 countries during the 2019–2020 influenza season to assess the uptake history of influenza vaccination. Among 287 participants, only 87 (30%) children with JIA received the influenza vaccine during the 2019–2020 season. Children who were more likely to be vaccinated were those with systemic juvenile idiopathic arthritis (sJIA), a history of previous vaccination and those aware of the vaccination recommendations. Conversely, children who previously experienced adverse vaccine-related events reported the lowest uptake. The primary reason for non-vaccination was lack of awareness about the necessity of influenza vaccination. Conclusion: Despite variations among countries, the uptake of influenza vaccines remains low in children with JIA. Improving awareness among families about the importance of influenza vaccination may increase vaccination rates in children with rheumatic diseases. What is Known: • Rheumatic children are at increased risk for influenza infection due to immunosuppressive therapy and immune dysregulation. • Influenza vaccine is formally recommended to children with rheumatic diseases. What is New: • This multicentre study showed that influenza vaccine uptake rates remain suboptimal among children with Juvenile Idiopathic Arthritis despite formal recommendations. • Factors like previous experience with vaccination and information provided by medical professionals via different ways play essential roles in increasing vaccination rates and can contribute to improved health outcomes for these vulnerable children. [ABSTRACT FROM AUTHOR]

To investigate the short-term and long-term effectiveness of different levels of financial incentives on increasing the willingness to vaccinate and vaccine uptake. A randomized controlled trial was conducted to investigate the effectiveness of financial incentives of three groups with monetary incentives (CNY 20, CNY 40, and CNY 60; 1 CNY = 0.13 EUR) vs. a control group—CNY 0—on influenza vaccine uptake among 720 older adults (≥60 years) in Beijing, China. The primary outcome was vaccine uptake, and the secondary outcomes were intention to vaccinate and length of time to immunization. Financial incentive significantly promoted higher intention to influenza vaccination (120/178 [67.42%] vs. 442/542 [81.55%]; Relative Risk [RR], 1.21; 95% CI, 1.02–1.42) and higher vaccination participation (74/178 [41.57%] vs. 316/542 [58.30%]; RR, 1.39; 95% CI, 1.10–1.75). CNY 60 had the largest impact on the intention to vaccinate (15.00% vs. 13.48% and 13.90%) and vaccination uptake (19.42% vs. 14.05% and 16.67%) compared with CNY 20 and CNY 40. Time to vaccination was significantly lower among participants receiving incentives than those without ([37.21 days; 95% CI, 34.33–39.99] vs. [48.27 days; 95% CI, 43.47–53.07]; Hazard Ratio [HR] 1.57, 95% CI 1.22–2.03). We found no long-term influence of financial incentives on vaccination decisions in the following year (217/542, 40.04% vs. 65/178, 36.52%; RR 1.08, 95% CI 0.82–1.42). Our study suggests that modest financial incentives will boost short-term influenza vaccination rates and shorten the length of time to immunization in China. No one single-time financial incentive had a long-term effect on future vaccination behaviours or helped establish regular vaccination behaviours. [ABSTRACT FROM AUTHOR]

Copyright of Annali di Igiene, Medicina Preventiva e di Comunità is the property of Societa Editrice Universo s.r.l. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vaccine immunogenicity and reactogenicity depend on recipient and vaccine characteristics. We hypothesized that healthy adults reporting higher reactogenicity from seasonal inactivated influenza vaccine (IIV) developed higher antibody titers compared with those reporting lower reactogenicity. We performed a secondary analysis of a randomized phase 1 trial of a trivalent IIV delivered by microneedle patch (MNP) or intramuscular (IM) injection. We created composite reactogenicity scores as exposure variables and used hemagglutination inhibition (HAI) titers as outcome variables. We used mixed-model analysis of variance to estimate geometric mean titers (GMTs) and titer fold change and modified Poisson generalized estimating equations to estimate risk ratios of seroprotection and seroconversion. Estimates of H3N2 GMTs were associated with the Systemic and Local scores among the IM group. Within the IM group, those with high reaction scores had lower baseline H3N2 GMTs and twice the titer fold change by day 28. Those with high Local scores had a greater probability of seroconversion. These results suggest that heightened reactogenicity to IM IIV is related to low baseline humoral immunity to an included antigen. Participants with greater reactogenicity developed greater titer fold change after 4 weeks, although the response magnitude was similar or lower compared with low-reactogenicity participants. [ABSTRACT FROM AUTHOR]

Background: COVID-19 is an infectious disease caused by SARS-CoV-2. It is unclear whether influenza vaccination reduces the severity of disease symptoms. Previous studies have suggested a beneficial effect of influenza vaccination on the severity of COVID-19. The aim of this study was to evaluate the possible protective effect of the influenza vaccine on the occurrence of SARS-CoV-2 infection symptoms and prognosis in patients hospitalized with COVID-19. Methods: This was a retrospective cohort study of patients who tested positive for SARS-CoV-2, identified by quantitative real-time polymerase chain reaction. Chi-square tests, Kaplan–Meier analysis, and multivariate analysis were performed to assess the association between influenza vaccination and the presence of symptoms in hospitalized patients with COVID-19 and their outcome. Results: In this study, 1712 patients received positive laboratory tests for SARS-CoV-2; influenza vaccination was a protective factor against the presence of characteristic COVID-19 symptoms such as polypnea, anosmia, dysgeusia, and fever (p < 0.001). Influenza-vaccinated patients had fewer days of hospitalization (p = 0.029). Conclusions: The findings of this study support that influenza vaccination is associated with a decrease in the number of symptoms in patients hospitalized due to COVID-19, with fewer days of hospitalization, but not with the outcome of disease. [ABSTRACT FROM AUTHOR]

Notwithstanding prevalence gaps in micronutrients supporting immune functions, the significance of their deficits/supplementation for the efficacy of vaccines is underinvestigated. Thus, the influence of supplementation combining vitamins C and D, zinc, selenium, manganese, and N-acetyl cysteine on immune correlates/surrogates of protection conferred by a quadrivalent influenza vaccine (QIV) in mice was investigated. The supplementation starting 5 days before the first of two QIV injections given 28 days apart increased the serum titres of total and neutralizing IgG against each of four influenza strains from QIV. Accordingly, the frequencies of germinal center B cells, follicular CD4+ T helper (Th) cells, and IL-21-producing Th cells increased in secondary lymphoid organs (SLOs). Additionally, the supplementation improved already increased IgG response to the second QIV injection by augmenting not only neutralizing antibody production, but also IgG2a response, which is important for virus clearance, through favoring Th1 differentiation as indicated by Th1 (IFN-γ)/Th2 (IL-4) signature cytokine level ratio upon QIV restimulation in SLO cell cultures. This most likely partly reflected antioxidant action of the supplement as indicated by splenic redox status analyses. Thus, the study provides a solid scientific background for further research aimed at repurposing the use of this safe and inexpensive micronutrient combination to improve response to the influenza vaccine. [ABSTRACT FROM AUTHOR]

Objective To investigate the influenza vaccination willingness and influencing factors among elderly patients with chronic diseases in Chongqing, providing a scientific basis for the development of targeted vaccine policies and intervention measures. Methods A multi 一 stage sampling method was employed to randomly select 1 280 elderly patients with chronic diseases in five districts of Chongqing for an investigation into their influenza vaccination willingness. Univariate analysis was performed using the t 一 test and chi 一 square test, and binary logistic regression analysis and the standardized score were used to analyze the influencing factors of influenza vaccination willingness among elderly patients with chronic diseases. Results Of the 1 211 eligible survey respondents, only 13. 1% of elderly patients with chronic diseases had received the influenza vaccination during the 2022 - 2023 influenza season, and 56. 3% were willing to receive the influenza vaccination in the 2023 一 2024 influenza season. The willingness to receive influenza vaccination among elderly patients with chronic diseases was higher among ethnic minorities (OR 二 3. 49, 95% CZ: 1, 21 - 10. 02), households or unemployed individuals (OR 二 2. 53, 95% Cl: 1. 05 - 6. 09), individuals with an average monthly household income per capita exceeding 5 000 RMB (OR 二 2. 86, 95% CI11. 33 - 6. 13), those with qualified knowledge of influenza vaccination (OR - 1. 38, 95% CI: 1. 02 - 1. 87), and under the policy of free vaccination (OR 二 56. 97, 95% CI: 24. 38 - 133.09). The behavioral and social drivers (BeSD) survey indicated that the belief in the effectiveness and safety of the influenza vaccine and fear of infecting friends or family members were the primary driving factors of influenza vaccine uptake, while the perception of the high costs of influenza vaccination was the most significant barrier. Conclusion The influenza vaccination willingness among elderly patients with chronic diseases in Chongqing needs further improvement. Governmental authorities, healthcare institutions, and communities should enhance the dissemination of knowledge about influenza vaccines, enhance social support, implement subsidies or free vaccination policies for priority populations, and encourage proactive influenza vaccine uptake among elderly patients with chronic diseases. [ABSTRACT FROM AUTHOR]

Within influenza vaccine effectiveness (VE) studies at primary care level with a laboratory-confirmed outcome, clinical case definitions for recruitment of patients can vary. We used the 2022–23 VEBIS primary care European multicentre study end-of-season data to evaluate whether the clinical case definition affected IVE estimates. We estimated VE using a multicentre test-negative case-control design. We measured VE against any influenza and influenza (sub)types, by age group (0–14, 15–64, ≥65 years) and by influenza vaccine target group, using logistic regression. We estimated IVE among patients meeting the European Union (EU) acute respiratory infection (ARI) case definition and among those meeting the EU influenza-like illness (ILI) case definition, including only sites providing information on specific symptoms and recruiting patients using an ARI case definition (as the EU ILI case definition is a subset of the EU ARI one). We included 24 319 patients meeting the EU ARI case definition, of whom 21 804 patients (90 %) meet the EU ILI case definition, for the overall pooled VE analysis against any influenza. The overall and influenza (sub)type-specific VE varied by ≤2 % between EU ILI and EU ARI populations. Among all analyses, we found similar VE estimates between the EU ILI and EU ARI populations, with few (10%) additional non-ILI ARI patients recruited. These results indicate that VE in the 2022–23 influenza season was not affected by use of a different clinical case definition for recruitment, although we recommend investigating whether this holds true for next seasons. [ABSTRACT FROM AUTHOR]

Psychological distress has been associated with dampened antibody production following vaccination. Questions remain, however, about whether psychological distress influences vaccine response uniformly across the lifespan, and whether changes in distress result in changes in antibody production across the same period. Participants (N = 148; M age = 32.2 years, SD = 19.7, range = 12–80 years) took part in consecutive vaccine studies during the 2017–2018 and 2018–2019 influenza seasons. Each influenza season, they reported on their depressive symptoms, provided blood samples, and received the standard influenza vaccine. Participants then provided a second blood sample one month later. Antibody titers were examined pre- and post-vaccination. Analyses examined both within-season and across-season effects of depressive symptoms, age, and their interaction on vaccine response. Within-season analyses revealed that age predicted antibody response during both seasons (2017–2018 and 2018–2019). Neither depressive symptoms nor the interaction with age were associated with antibody response to vaccination within either season. Across the two seasons, age significantly moderated the association between change in depressive symptoms and change in antibody production. For people who were 48 or older, increases in depressive symptoms across the two seasons were associated with a less robust response to the vaccine in the second season relative to the first season. For people younger than 48, changes in depressive symptoms were not significantly related to changes in antibody production. These findings highlight the important role of mental health for older adults' vaccine response, which could have clinical relevance for protection against disease. [ABSTRACT FROM AUTHOR]

Background: Pediatricians' offices are primary locations for pediatric influenza vaccination; however, pharmacists are also well-positioned as immunizers. Considering the current COVID-19 pandemic and Public Readiness and Emergency Preparedness (PREP) Act, pharmacists' authority to vaccinate children has been recently expanded. Methods: We used the de-identified Optum ClinformaticsTM Data Mart database to identify demographic and clinical predictors of pharmacist-administered pediatric influenza vaccination compared with influenza vaccination in pediatricians' offices. Procedures codes for influenza vaccinations among children were captured for the 2016-2017 influenza season. Logistic regression was used to identify significant predictors. Results: We included 336 841 children receiving influenza vaccines by a pharmacist (5.2%) or in pediatricians' offices (94.8%). The following significant predictors were identified: older pediatric age groups (13-17 years odds ratio [OR] 91.51, 5-12 years OR 35.41), states allowing pharmacist-administered influenza vaccination at younger ages (no age restrictions OR, 26.68, minimum age 2-4 years old OR, 33.76), influenza vaccination outside of pediatricians' offices in the previous year (pharmacist-administered OR, 22.18, convenience care OR 4.15, emergency care OR 1.69), geographic region (South OR, 2.02, Midwest OR 1.60, and West OR 1.38), and routine health exam or follow-up in the prior 6-months (OR, 1.59). Conclusions: The strongest drivers of pharmacist-administered pediatric influenza vaccination were older pediatric age, more lenient minimum age restrictions, and previous influenza vaccination in a pharmacy. Due to the COVID-19 pandemic, the PREP Act, and forthcoming pediatric COVID-19 vaccines for children, pharmacists may play a greater role in pediatric vaccination resulting in sustained changes in pediatric vaccination practices. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus (DM) patients are prone to influenza infection. Seasonal vaccination is the most effective method to prevent influenza. Assessing the influenza coverage and the knowledge and attitude of patients toward it will help in raising the coverage and decreasing the complications. Objectives: To detect the level of influenza vaccination coverage among people with type 2 diabetes mellitus (T2DM) and assess the knowledge about influenza infection and attitude toward influenza vaccine among those patients. Methods: We conducted a cross-sectional study in the diabetes outpatient clinics at Zagazig University hospitals. The study included 327 diabetic patients. It took six months, from February to July 2023. A structured questionnaire was used to assess knowledge, attitudes, and practices regarding seasonal influenza vaccination and factors that may affect them. Results: The mean age of participants was 55.2 years; most of them were female (63.3%). The vaccination coverage was only 23.9%. Sufficient knowledge was reported (64.8%), and a positive attitude toward vaccination among those who had heard about it was reported (69.6%). The main cause of non-vaccination was that they didn't hear about the vaccine (67.8%), while the main cause of vaccination was a doctor's advice (62.8%). After logistic regression, sufficient knowledge and longer disease duration were found to be statistically significant predictors for vaccination (odds ratio 2.117, 1.081 respectively). Conclusions: The influenza vaccination rate among T2DM patients is below the optimal level. Overall, knowledge and attitude toward the influenza vaccine among diabetic patients should be raised. [ABSTRACT FROM AUTHOR]

Annual influenza vaccination is crucially recommended for the elderly to maintain humoral immunity. Insufficient coverage requires us to understand the determinants of their influenza behaviors and how these patterns impact vaccination choices. Data from 540 Beijing residents aged over 65 were collected through interviews, capturing vaccination history and sociodemographic details. Individual influenza vaccination records from 2016 to 2020 were obtained from China's Immunization Information Systems. A latent class model identified three vaccination patterns. Multinomial logistic regression assessed relative risk ratios (RRRs) for vaccination based on sociodemographic factors. Vaccination patterns were used to predict future vaccination likelihood. The analysis revealed three groups: sporadically vaccinated (63.33%), occasionally vaccinated (18.71%), and frequently vaccinated (17.96%). Factors associated with frequent vaccination included age over 70 (RRR = 2.81), lower income (RRR = 0.39), higher vaccine hesitancy (RRR = 3.10), multiple chronic conditions (RRR = 2.72), and rural residence (RRR = 2.48). The frequently vaccinated group was more likely to sustain regular vaccination habits in subsequent years compared to the occasionally vaccinated group. Only 17.96% of Beijing's older population exhibited a consistent influenza vaccination pattern. Older age, rural residency, and chronic diseases correlated with repeated influenza vaccination. Segmenting the population based on past vaccination behavior can aid in designing targeted interventions to improve vaccination rates. [ABSTRACT FROM AUTHOR]

Aims: Takotsubo syndrome (TTS) is a rare complication of vaccination. In this study, we sought to provide insight into the characteristics of reported TTS induced by vaccination. Methods and results: We did a systematic review, searching PubMed, Embase, Web of Science, Ovid MEDLINE, Journals@Ovid, and Scopus databases up to 26 April 2023 to identify case reports or case series of vaccine‐induced TTS. We then extracted and summarized the data from these reports. Eighteen reports were identified, with a total of 19 patients with TTS associated with vaccinations. Of the 19 included patients, the majority were female (n = 13, 68.4%) with a mean age of 56.6 ± 21.9 years. Seventeen patients developed TTS after coronavirus disease 2019 vaccination, 14 of whom received an mRNA vaccination. Two cases of TTS occurred after influenza vaccination. Among the 19 patients, 17 (89.5%) completed transthoracic echocardiography and 16 (84.2%) underwent angiography procedures. Seven patients (36.8%) completed cardiac magnetic resonance imaging. The median time to symptom onset was 2 (inter‐quartile range, 1–4) days. The most common symptoms were chest pain (68.4%), dyspnoea (57.9%), and digestive symptoms (31.6%). A total of 57.9% of patients developed nonspecific symptoms such as fatigue, myalgia, diaphoresis, and fever. Among the 16 reported cases of TTS, 15 patients (93.8%) exhibited elevated cardiac troponin levels, while among the nine reported cases, eight patients (88.9%) had elevated natriuretic peptide levels. All patients had electrocardiographic changes: ST‐segment change (47.1%), T‐wave inversion (58.8%), and prolonged corrected QT interval (35.3%). The most common TTS type was apical ballooning (88.2%). Treatment during hospitalization typically included beta‐blockers (44.4%), angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers (33.3%), and diuretics (22.2%). After treatment, 81.3% of patients were discharged with improved symptoms. Among this group, nine patients (56.3%) were reported to have recovered ventricular wall motion during follow‐up. Two patients (12.5%) died following vaccination without resuscitation attempts. Conclusions: TTS is a rare but potentially life‐threatening complication of vaccination. Typical TTS symptoms such as chest pain and dyspnoea should be considered alarming symptoms, though nonspecific symptoms are common. The risks of such rare adverse events should be balanced against the risks of infection. [ABSTRACT FROM AUTHOR]

In this study, we evaluated sex differences during infection with mouse-adapted H1N1 and H3N2 influenza A viruses (IAVs) in the C57BL/6J mouse model and compared the cytokine and antibody responses between plasma and serum samples during IAV infection and vaccination. Lethal doses for both H1N1 and H3N2 IAVs were lower for adult females and they suffered with greater morbidity than adult males when infected with sublethal doses. In influenza virus-infected mice, cytokine responses differed between plasma and serum samples. After inactivated influenza virus vaccination and drift variant challenge, adult female mice had greater antibody responses and were better protected. In influenza-vaccinated and challenged mice, binding antibodies were unaffected between paired plasma or serum samples. However, functional antibody assays, including hemagglutination inhibition, microneutralization, and antibody-dependent cellular cytotoxicity assays, were affected by the use of plasma and serum sample types. Our results indicate that careful consideration is required while selecting plasma versus serum samples to measure cytokine and antibody responses during IAV infection and vaccination. [ABSTRACT FROM AUTHOR]

BACKGROUND: Influenza vaccination is recommended for adults regardless of human immunodeficiency virus (HIV) status. There may be facilitators or barriers to vaccinating people with HIV (PWH) that differ from people without HIV (PWoH). We sought to describe the uptake of influenza vaccination by HIV status and identify factors associated with vaccination. METHODS: We abstracted data from the electronic health records of PWH and PWoH in Kaiser Permanente Northern California during 6 influenza seasons (2013-2018). We determined vaccination uptake and used Poisson regression models to evaluate factors associated with vaccination in PWH and PWoH. RESULTS: 9272 PWH and 194 393 PWoH matched by age, sex, and race/ethnicity were included (mean age: 48 vs 49 years; men: 91% vs 90%; White race: 53% for both groups). PWH were more likely to receive the influenza vaccine (65-69% across years for PWH and 37-41% for PWoH) with an adjusted risk ratio for all years of 1.48 (95% CI: 1.46-1.50). For PWH, lower vaccination uptake was associated with several factors that suggested more complex health needs, such as lower CD4 cell counts, higher HIV viral loads, prior depression diagnoses, having Medicare insurance, and having a higher number of comorbidities. Associations with vaccination uptake were attenuated in PWH, compared with PWoH, for smoking, alcohol, and demographic factors. CONCLUSIONS: PWH had an almost 50% higher uptake of influenza vaccination than PWoH, possibly reflecting greater engagement with the healthcare system. We also found that PWH with more complex health needs had reduced vaccination uptake. Findings may inform outreach strategies to increase influenza vaccination in PWH.

BackgroundSeasonal influenza continues to pose a substantial public health challenge for older adults residing in rural areas worldwide. Vaccination remains the most efficacious means of preventing influenza. This study aimed to investigate the extent of influenza vaccine coverage and identify the factors influencing vaccine uptake among older adults in rural regions of south China.MethodsA cross-sectional study utilizing convenience sampling was conducted in two rural sites in Guangdong Province. Individuals needed to meet specific inclusion criteria: (1) attainment of 60 years of age or older; (2) originating from rural households; (3) demonstrating a voluntary desire to partake in the survey, either through written or verbal informed consent. Data encompassed variables such as socio-demographic information, influenza infection and vaccination history, knowledge and attitudes toward influenza vaccination, and perceived beliefs regarding the influenza vaccine. Univariate and multivariable logistic regression analyses were employed to ascertain the factors associated with influenza vaccine utilization. In the multivariable model, adjustments were made for gender, age, legal marital status, highest educational attainment, and monthly income.ResultsA total of 423 participants were ultimately included in this study, with the majority falling within the age range of 60–75 years (81.3%). Only one-third of the participants had received an influenza vaccine in the past year (30.0%). Notably, nearly half of the older adults exhibited hesitancy toward influenza vaccination (45.1%). The multivariable analysis revealed that rural older people with a robust understanding of influenza vaccines and a positive attitude toward them (adjusted odds ratio [aOR] = 2.60, 95% confidence interval [CI]: 1.41–4.81), along with a high level of trust in vaccination service providers (aOR = 2.58, 95% CI: 1.01–6.63), were positively associated with receiving influenza vaccination in the past year.ConclusionThis study reveals a low rate of influenza vaccine uptake among older adults residing in rural areas of south China. Given the limited adoption of influenza vaccination and the significant threat it poses, there is an urgent imperative to devise precise interventions aimed at enhancing the effectiveness of influenza vaccination programs.

ABSTRACT: Objectives: In order to support policymakers in allocating resources, we aimed to assess vaccine effectiveness (VE) of inactivated influenza vaccines (IIVs) available for Italian adults in the 2023/2024 season. Methods: A hospital-based test-negative case-control study was conducted in Genoa between mid-October 2023 and mid-April 2024. Adult (≥18 years) inpatients with prescription of a polymerase chain reaction test for influenza were eligible. Results: Of 1,664 adults analyzed, most (82%) of which were ≥65 years, 114 (6.9%) tested positive for influenza A. Most (92%) cases were caused by subclades 6B.1A.5a.2a and 6B.1A.5a.2a.1 of the A(H1N1)pdm09 subtype. In older adults aged ≥65 years vaccination was effective at 51% (95% CI: 8%, 74%) against any influenza A and 49% (95% CI: 2%, 73%) against A(H1N1)pdm09. Compared with non-vaccinated older adults, VE point estimates for the adjuvanted and, especially, high-dose IIVs were higher than those for the standard-dose non-adjuvanted IIV. Conclusion: The 2023/2024 seasonal influenza vaccination proved moderately effective in preventing hospitalization for laboratory-confirmed influenza. Being more appropriate for older adults, local policymakers and vaccinating physicians should maximize adoption of the enhanced IIVs.

Objective To construct a universal influenza mRNA vaccine and evaluate its immunogenicity. Methods The antigen sequence of hemagglutinin (HA), nucleoprotein (NP) and matrix protein 2 ectodomain (M2e) in influenza A/California/04/2009 was optimized.HA, NP and 3 tandem M2e (3M2e) were cloned into pcDNA3.1 vector, respectively.Then the mRNAs were synthesized by linearization, in vitro transcription, enzymatic capping and enzymatic tailing, and named as mRNA-HA, mRNA-NP and mRNA-3M2e, respectively.The protein expression of the 3 kinds of mRNAs in 293T cells was detected by immunofluorescence assay.Comb-mRNA vaccine was prepared by enveloped mRNA-HA, mRNA-NP and mRNA-3M2e with lipid nanoparticles, respectively, and the particle size and potential were identified.Twenty-eight 6-week-old female BALB/c mice (18~22 g) were randomly divided into LNP group (n=14) and Comb-mRNA group (n=14).Hemagglutination inhibition (HI) method and microneutralization (MN) test were used to evaluate the serum antibody titer induced by Comb-mRNA vaccines.The mice were infected by 5LD50 wild-type H1N1 influenza virus to evaluate the protective efficacy. Results The mRNA-HA, mRNA-NP and mRNA-3M2e were successfully constructed, and the 3 mRNAs could be expressed in 293T cells.The average size of mRNA encapsulated by lipid nanoparticles was 119.53±6.5 nm, and the average potential was-8.23±1.3 mV.The geometric mean titer (GMT) of HI and MN in the Comb-mRNA group were 179.6 and 201.6, compared with the LNP group.The ratio of IFN-γ+CD4+/CD8+T cells was increased.The Comb-mRNA group could provide protection against 5LD50 wild type influenza H1N1 virus after 2 weeks of booster immunization. Conclusion Comb-mRNA, an influenza vaccine candidate, can induce immune responses and protect mice from influenza virus challenge.

Abstract Background Despite the increased recommendations for influenza vaccination, particularly among high-risk groups such as young children, Yemen lacks an influenza vaccination program, and the influenza vaccine is not included in the national immunization regime. This is exacerbated by the country’s fragile infrastructure, as well as the devastating consequences of the ongoing conflict, which include child undernutrition and strained healthcare resources. Thus, the objective of the current study is to assess the public attitudes and perceptions toward vaccinating children against influenza in Yemen. Methods A cross-sectional study was conducted by distributing a validated survey questionnaire to potential participants using convenience sampling. Descriptive statistics were used to summarize sociodemographic data, knowledge of influenza vaccines, and attitudes and perceptions regarding vaccinating children against influenza. Logistic regression analysis was employed to identify associations between independent variables and the acceptance of vaccines for children. Results A total of 853 eligible individuals, parents and non-parents, successfully completed the survey. The uptake of the influenza vaccine among the participants was notably low as the majority (69.2%) had not previously received the vaccine, although the majority expressed a willingness to get vaccinated in the future (59.4%). The majority (68.5%) were willing to vaccinate children. The largest percentage of the participants who expressed hesitancy toward children’s vaccination cited multiple reasons to reject the vaccine (39.7%), with concerns regarding the safety of the vaccine being the predominant barrier to its acceptance for children (29.6%). On the other hand, motivating factors for vaccinating children included the validation of the vaccine’s safety and efficacy, endorsement of the vaccine by the government and physicians, integration of the vaccine into the national immunization program, and the provision of the vaccine free of charge and through schools. Significant predictors for vaccine acceptance in children included male gender, knowledge of the protective effect of the influenza vaccine, previous receipt of the vaccine, and a willingness to receive the vaccine in the future. Conclusions The study highlights the need for educational health campaigns to raise awareness and remove misconceptions regarding influenza and the role, benefits, and availability of its vaccine. These findings can serve as a robust foundation for the future design and implementation of an influenza vaccination program for children in Yemen.

The onset of COVID-19 has had a profound impact on the world, leading to significant adjustments in human behavior. A plethora of behavioral modifications have been embraced by individuals. As COVID-19 symptoms are similar to influenza symptoms, this study aimed to measure attitudes regarding the uptake of influenza vaccination in the COVID-19 era. This cross-sectional study used a self-administered questionnaire. A total of 311 participants were conveniently selected from two of the most popular shopping malls in Jeddah City, Saudi Arabia, during a three-day influenza awareness campaign conducted between 11 November 2020 to 14 November 2020. Demographic items and all scales (summed and examined for internal reliability using Cronbach’s alpha) were analyzed using univariate analysis, including measures of central tendencies and frequencies. This study indicates that the COVID-19 pandemic has not significantly affected vaccination adoption rates. Only 9.3% of the individuals who received the vaccine expressed fear or a desire for protection against COVID-19.

Resumen: Introducción: la vacunación antigripal es una medida efectiva pare reducir ingresos hospitalarios y mortalidad. El objetivo de este estudio es cuantificar la efectividad de la vacunación antigripal en pacientes hospitalizados por gripe para evitar su evolución a gravedad, considerando otros factores conocidos que influyen sobre esa gravedad. Métodos: estudio transversal de las temporadas epidemiológicas gripales 2016-2017 a 2019-2020 con pacientes hospitalizados en el Hospital Universitario Nuestra Señora de la Candelaria de Tenerife diagnosticados de gripe. Se estudiaron variables demográficas y de evolución básicas. El criterio de gravedad clínica empleado es el establecido por el Centro Nacional de Epidemiología de España. Mediante regresión logística binaria multivariable se estimó el riesgo de evolución a gravedad asociado al estado vacunal antigripal. Resultados: se recopilaron 1.416 pacientes, mujeres el 50%, mayores de 64 años el 56%, 17% con vacunación antigripal, 24% evolucionaron a gravedad, 3% fallecieron, 72% tratados con oseltamivir, 23% (IC95%: 19–27) no tratados con oseltamivir ingresaron en UCI, frente a 1,5% (IC95%: 1–2) sí tratados. Evolucionaron a gravedad el 25% (IC95%: 23–28) de no vacunados, frente al 18% (IC95%: 13–23) de vacunados. La odds ratio (OR) a evolución grave fue de 1,6 (IC95%: 1,1-2,2) para los no vacunados. Conclusiones: el paciente hospitalizado por gripe que no ha recibido vacunación antigripal presenta más del doble de riesgo a una evolución grave de la gripe frente al correctamente vacunado. La combinación de oseltamivir y vacunación reduce en casi un quinto su ingreso en la UCI. Abstract: Introduction: Influenza vaccination is an effective measure to reduce hospital admissions and mortality. The objective of this study is to quantify the effectiveness of influenza vaccination in patients hospitalized for influenza to prevent its evolution to severity, considering other known factors that influence such severity. Methods: Cross-sectional study of the 2016–2017 to 2019–2020 influenza epidemiological seasons with patients hospitalized at the Nuestra Señora de la Candelaria University Hospital in Tenerife diagnosed with influenza. Basic demographic and evolution variables were studied. The criteria for clinical severity used is that established by the Spanish National Epidemiology Center. Using multivariable binary logistic regression, the risk of progression to severity associated with influenza vaccination status was estimated. Results: A total of 1,416 patients were collected. Of whom 50% were women, 56% older than 64 years, 17% with flu vaccination, 24% evolved to severity, 3% died, 72% treated with oseltamivir, 23% (CI95%: 19–27) not treated with oseltamivir were admitted to the ICU, compared to 1.5% (CI95%: 1–2) treated, 25% (CI95%: 23–28) of the non-vaccinated patients developed severity, compared to 18% (CI95%: 13–23) of the vaccinated. The odds ratio (OR) to severe evolution was 1.6 (CI95%: 1.1–2.2) for those not vaccinated. Conclusions: Patients hospitalized for influenza who have not received influenza vaccination have a more than double the risk of a serious evolution of influenza compared to correctly vaccinated patients. The combination of oseltamivir and vaccination reduces their admission to the ICU by almost a fifth.

The AS03-adjuvanted H5N1 influenza vaccine induces significantly higher immune responses compared to the non-adjuvanted H5N1 vaccine. However, the immunological mechanisms underlying this enhancement remain unclear. We aimed to identify the key genes and pathways involved in the immune response to the AS03-adjuvanted H5N1 vaccine compared to the non-adjuvanted H5N1 vaccine. The expression profiles of GSE102012 and GSE112293 were downloaded from the Gene Expression Omnibus database to identify differentially expressed genes between AS03-adjuvanted and non-adjuvanted H5N1 vaccine groups. Subsequently, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the Database for Annotation, Visualization, and Integrated Discovery online tool. The protein–protein interaction (PPI) networks were constructed by the Search Tool for the Retrieval of Interacting Genes database. Through cluster analysis of the PPI network, three hub genes, namely NR4A1, SDC1, and ID3, were identified as pivotal players in the intricate network of interactions. The ID3 was up-regulated, and the other two hub genes were down-regulated. The results of the GO analysis highlighted enrichment in seven biological processes, three cellular components, and two molecular functions among the differentially expressed genes. The KEGG pathway analysis revealed the involvement of the Cushing syndrome pathway. The AS03-adjuvanted H5N1 vaccine may enhance immune responses through suppressing the NR4A1 gene and the SDC1 gene, upregulating the ID3 gene, and reducing cortisol production compared to the non-adjuvanted H5N1 vaccine.