Association between combination COVID-19-influenza vaccination and long COVID in middle-aged and older Europeans: A cross-sectional study.

The potential impact of combined COVID-19 and influenza vaccination on long COVID remains uncertain. In the present cross-sectional study, we aimed to investigate the plausible association between them in middle-aged and older Europeans based on the Survey of Health, Ageing, and Retirement in Europe (SHARE). A total of 1910 participants were recruited in the analyses. The study outcome was long COVID. Participants were divided into 4 groups through the self-reported status of COVID-19 and influenza vaccination. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated. 1397 participants experienced long COVID. After multivariable adjustment, those vaccinated with neither COVID-19 nor influenza vaccine had higher risk of long COVID (OR, 1.72; 95% CI, 1.26-2.35) compared to those vaccinated with both vaccines. Furthermore, adding the 4 statuses of COVID-19 vaccination/influenza vaccination to conventional risk model improved risk reclassification for long COVID (continuous net reclassification improvement was 16.26% [p = .003], and integrated discrimination improvement was 0.51% [p = .005]). No heterogeneity was found in the subgroup analyses (all p-interaction ≥0.05). Our study might provide a strategy for people aged 50 and over to reduce the occurrence of long COVID, that is, to combine the use of the COVID-19 vaccine and influenza vaccines.

Evaluating the impact of school-based influenza vaccination programme on absenteeism and outbreaks at schools in Hong Kong: a retrospective cohort study protocol.

INTRODUCTION: Seasonal influenza causes annual school breaks and student absenteeism in Hong Kong schools and kindergartens. This proposal aims to conduct a retrospective cohort study to evaluate the impact of a school-based influenza vaccination (SIV) programme on absenteeism and outbreaks at schools in Hong Kong. METHODS: The study will compare schools that implemented the SIV programme with schools that did not. The data will be sourced from school records, encompassing absenteeism records, outbreak reports, and vaccination rates. We will recruit 1000 students from 381 schools and kindergartens in 18 districts of Hong Kong starting June 2024. The primary outcome measures will include absenteeism rates due to influenza and school influenza outbreaks. Secondary outcomes will consist of vaccination coverage rates and the impact of the SIV programme on hospitalisations due to influenza-like illness. A t-test will be conducted to compare the outcomes between schools with and without the SIV programme. ETHICS AND DISSEMINATION: The school completed signing the participants' informed consent form before reporting the data to us. Our study has been approved by the Hospital Authority Hong Kong West Cluster IRB Committee (IRB No: UW 17-111) and was a subtopic of the research "The estimated age-group specific influenza vaccine coverage rates in Hong Kong and the impact of the school outreach vaccination program". TRIAL REGISTRATION: This study will be retrospectively registered.

Cost-effectiveness of the adjuvanted quadrivalent influenza vaccine for older adults in South Korea.

South Korea's National Immunization Program administers the quadrivalent influenza vaccine (QIV) to manage seasonal influenza, with a particular focus on the elderly. After reviewing the safety and immune response triggered by the adjuvanted QIV (aQIV) in individuals aged 65 and older, the Ministry of Food and Drug Safety in Korea approved its use. However, the extensive impact of aQIV on public health is yet to be fully understood. This study assessed the cost-effectiveness of replacing QIV with aQIV in South Korean adults aged 65 years and older. A dynamic transmission model, calibrated with national influenza data, was applied to compare the influence of aQIV and QIV on older adults and the broader population throughout a single influenza season. This study considered both the direct and indirect effects of vaccination on the elderly. We derived the incremental cost-effectiveness ratios (ICERs) from quality-adjusted life-years (QALYs) and costs incurred, validated through a probabilistic sensitivity analysis with 5,000 simulations. Findings suggest that transitioning to aQIV from QIV in the elderly would be cost-effective, particularly if aQIV's efficacy reaches or exceeds 56.1%. With an ICER of $29,267/QALY, considerably lower than the $34,998/QALY willingness-to-pay threshold, aQIV presents as a cost-effective option. Thus, implementing aQIV with at least 56.1% efficacy is beneficial from both financial and public health perspectives in mitigating seasonal influenza in South Korea.

Consensus statements for influenza awareness, prevention, and vaccination in Pakistan.

INTRODUCTION: Influenza is a serious underestimated viral infection in Pakistan and influenza vaccination and vaccination awareness are low. The current work aimed to develop consensus on influenza epidemiology, prevention, vaccination, and awareness in Pakistan. METHODOLOGY: A systematic literature search was conducted to develop recommendations on influenza vaccines in Pakistan. Experts' feedback was incorporated using the modified Delphi method. A three-step process was used, with 18 experts from different specialties from Pakistan who participated in voting rounds to achieve a minimum 75% agreement level. RESULTS: Pakistan has a low-immunization-rate and is susceptible to serious influenza outbreaks and influenza-related complications. Influenza circulates year-round in Pakistan but peaks during January and February. The subtype A/H1N1 is predominant. The experts urged vaccination in all individuals ≥ 6 months of age and with no contraindications. They highlighted special considerations for those with comorbidities and specific conditions. The experts agreed that the inactivated influenza vaccine is safe and efficient in pregnant women, immunocompromised, and comorbid respiratory and cardiovascular patients. Finally, the experts recommended conducting promotional and educational programs to raise awareness on influenza and vaccination. CONCLUSIONS: This is the first regional consensus on influenza and influenza vaccination in Pakistan with experts' recommendations to increase influenza vaccination and decrease influenza cases and its associated detrimental effects.

Effectiveness of inactivated influenza vaccine against laboratory-confirmed influenza among Chinese elderly: a test-negative design.

BACKGROUND: Evidence on the effectiveness of influenza vaccination in the elderly is limited, and results are controversial. There are also few reports from China. METHODS: We conducted a test-negative case-control study design to estimate influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated visits among elderly (aged ≥ 60 years) across four influenza seasons in Ningbo, China, from 2018 to 19 to 2021-22. Influenza-positive cases and negative controls were randomly matched in a 1:1 ratio according to age, sex, hospital, and date of influenza testing. We used logistic regression models to compare vaccination odds ratios (ORs) in cases to controls. We calculated the VE as [100% × (1-adjusted OR)] and calculated the 95% confidence interval (CI) around the estimate. RESULTS: A total of 30,630 elderly patients tested for influenza with virus nucleic acid or antigen during the study period. After exclusions, we included 1 825 influenza-positive cases and 1 825 influenza-negative controls. Overall, the adjusted VE for influenza-related visits was 63.5% (95% CI, 56.3-69.5%), but varied by season. Influenza VE was 59.8% (95% CI, 51.5-66.7%) for influenza A and 89.6% (95% CI, 77.1-95.3%) for influenza B. The VE for ages 60-69 and 70-79 was 65.2% (95% CI, 55.4-72.9%) and 69.8% (95% CI, 58.7-77.9%), respectively, but only 45.4% (95% CI, 6.2-68.2%) for ages 80 and over. CONCLUSIONS: Standard-dose inactivated influenza vaccine has shown good protection in the elderly in China. However, protection may not be satisfactory in people aged 80 years and older.

Analysis of the epidemiological situation of influenza in Guangzhou under the prevention and control of COVID-19 in June 2022.

OBJECTIVE: Under the prevention and control measures of COVID-19, the epidemiological situation of respiratory pathogens is not well known. Understanding the patterns of respiratory pathogens epidemiology under the prevention and control measures of COVID-19 is important to guide resource allocation for existing and future treatment and prevention strategies. METHODS: In total, 659 fever outpatients nasopharyngeal swabs were collected at fever illness onset during June in 2022 at the First Hospital of Guangzhou Medical University. Swabs were tested by real-time fluorescent single-tube multiplex polymerase chain reaction (PCR) for 12 respiratory pathogens. Moreover, 108 of the 659 swabs were tested for influenza virus antigen. RESULTS: At least one pathogen was detected in 477 (72.38%) of 659 fever outpatients with multiple pathogens identified in 25 (3.79%). The highest multiple infectious pattern is parainfluenza virus in combination with influenza (five cases). Influenza A virus (IFA), human rhinovirus (HRV), and parainfluenza virus are the three leading virus pathogens with proportions of 64.64%, 5.01%, and 2.88%. School-age children and adult groups have the highest pathogens positivity rate of 81.28% and 83.87%. CONCLUSION: A high proportion of adolescents and adults has respiratory pathogens detected during fever illnesses during June in 2022 under the prevention and control of COVID-19. These data indicate that diagnosis, prevention, and control of respiratory tract infection should be paid attention under the prevention and control of COVID-19.

The effect of oral probiotics on response to vaccination in older adults: a systematic review of randomised controlled trials.

This systematic review evaluated the impact of oral probiotics on the immune response to vaccination in older people. A literature search was performed in three electronic databases up to January 2023. Randomised controlled trials (RCTs) conducted in older people (age ≥ 60 years) investigating oral probiotics and vaccine response outcomes were included. Characteristics and outcome data of the included studies were extracted and analysed and study quality was assessed using the Cochrane Risk of Bias Tool for randomised trials. Ten RCTs involving 1,560 participants, reported in 9 papers, were included. Nine studies involved the seasonal influenza vaccine and one a COVID-19 vaccine. All studies used lactobacilli, some in combination with bifidobacteria. Studies reported outcomes including anti-vaccine antibody titres or concentrations, seroconversion and seroprotection. When comparing antibody titres, seroprotection rate and seroconversion rate between probiotic and placebo groups expressed as a response ratio, the weighted mean values were 1.29, 1.16 and 2.00, respectively. Meta-analysis showed that probiotics increase seroconversion rates to all three strains of the seasonal influenza vaccine: odds ratio (95% confidence interval) 2.74 (1.31, 5.70; P = 0.007) for the H1N1 strain; 1.90 (1.04, 3.44; P = 0.04) for the H3N2 strain; 1.72 (1.05, 2.80; P = 0.03) for the B strain. There was a low level of heterogeneity in these findings. Several studies were at high risk of bias due to missing outcome data. Lactobacilli may improve the vaccine response, but further research is needed to be more certain of this.

Exploring barriers to influenza vaccine uptake and recommendation among healthcare providers in the community in China: A qualitative study.

Healthcare providers (HCPs) are recommended for priority influenza vaccination due to their high risk of contracting influenza. HCPs greatly aid in targeted population immunization campaigns. Therefore, understanding the factors that influence HCPs' decisions to get vaccinated and to recommend influenza vaccination is essential. However, there currently needs to be more evidence on this topic in China. Qualitative interviews using a semi-structured interview method were conducted with 180 HCPs from urban community hospitals and town hospitals in four cities in Shandong Province during August 2023. The interview content was analyzed using thematic analysis to identify the variables impacting the vaccination and recommendation practices of HCPs, as well as their suggestions for improving vaccination services. The results will help support the future development of precise intervention measures as well as focused education and training.

End of 2022/23 Season Influenza Vaccine Effectiveness in Primary Care in Great Britain.

BACKGROUND: The 2022/23 influenza season in the United Kingdom saw the return of influenza to prepandemic levels following two seasons with low influenza activity. The early season was dominated by A(H3N2), with cocirculation of A(H1N1), reaching a peak late December 2022, while influenza B circulated at low levels during the latter part of the season. From September to March 2022/23, influenza vaccines were offered, free of charge, to all aged 2-13 (and 14-15 in Scotland and Wales), adults up to 49 years of age with clinical risk conditions and adults aged 50 and above across the mainland United Kingdom. METHODS: End-of-season adjusted vaccine effectiveness (VE) estimates against sentinel primary-care attendance for influenza-like illness, where influenza infection was laboratory confirmed, were calculated using the test negative design, adjusting for potential confounders. METHODS: Results In the mainland United Kingdom, end-of-season VE against all laboratory-confirmed influenza for all those > 65 years of age, most of whom received adjuvanted quadrivalent vaccines, was 30% (95% CI: -6% to 54%). VE for those aged 18-64, who largely received cell-based vaccines, was 47% (95% CI: 37%-56%). Overall VE for 2-17 year olds, predominantly receiving live attenuated vaccines, was 66% (95% CI: 53%-76%). CONCLUSION: The paper provides evidence of moderate influenza VE in 2022/23.

Effectiveness of cocoon strategy vaccination on prevention of influenza-like illness in young infants.

During the initial half-year of their existence, infants cannot receive the influenza vaccine, yet they face the greatest susceptibility to severe influenza complications. In this study, we seek to determine whether influenza vaccination of maternal and household contacts is associated with a reduced risk of influenza-like illness (ILI) and severe acute respiratory infection (SARI) in infants. This work was prospectively conducted during the influenza season. A total of 206 infants were included in this study. The percentage of infants with only the mother vaccinated is 12.6% (n:26), and the percent of infants with all household contacts vaccinated is 16% (n:33). Among the infants with only the mother vaccinated, the effectiveness of influenza vaccine is estimated as 35.3% for ILI and 41.3% for SARI. Among infants with all household contacts vaccinated, the effectiveness is estimated as 48.9% for ILI and 76.9% for SARI. Based on the results of multivariate logistic regression analysis, all-household vaccination is a protective factor against SARI (OR: 0.07 95% CI [0.01-0.56]), household size (OR: 1.75, 95% CI [1.24-2.48]) and presence of secondhand smoke (OR: 2.2, 95% CI [1.12-4.45]) significant risk factors for SARI in infants. The mother alone being vaccinated is not a statistically significant protective factor against ILI (OR: 0.46, 95% CI [0.19-1.18]) or SARI (OR: 0.3, 95% CI [0.11-1.21]). Along with the obtained results and analysis, this study provides clear evidence that influenza vaccination of all household contacts of infants aged 0-6 months is significantly associated with protecting infants from both ILI and SARI.

Quadrivalent Live-Attenuated Influenza Vaccine in Milan preschools: an Italian experience of school-located flu vaccination within the 2022-2023 season.

BACKGROUND: In Italy, since the 2020-2021 flu season, the flu vaccine recommendation was extended to all children aged 6 months to 6 years and quadrivalent Live-Attenuated Influenza Vaccine (qLAIV) was introduced. Since school-aged children are important carriers of annual influenza epidemics, a school-based influenza vaccination program may potentially increase vaccine uptake. Recent studies, conducted in the UK and the US, show that school-based vaccination can reach higher percentage of paediatric vaccination coverage compared to children vaccinated in other settings. METHODS: During 2022-2023 flu season in 9 preschools located in Milan healthcare personnel vaccinated children with qLAIV at the end of a school day. A Google Form questionnaire was administered to preschoolers' parents of all preschools within the Municipality of Milan. RESULTS: In the preschools engaged in the vaccination program, 233 out of 1939 children were vaccinated (12%). Among these, 61 (26.2%) had never been vaccinated for influenza before. Vaccination coverage was 11.5% for Italian children and 14.3% for children coming from an immigrant background. We collected 3659 questionnaire responses, divided according to study participation status (371 from preschools that participated in the vaccination program and 3288 from other preschools in Milan). 57% of the families who answered to the questionnaire vaccinated their children for flu. qLAIV accounted for 85.6% of vaccinations. We observed a statistically significant difference in the percentage of vaccinated children between those attending a school participating in the project (67.9%) and children attending other schools (56%) (p < 0.001). Vaccination was administered by family pediatricians (48.9%), in vaccination centers (34.8%), in vaccine hubs (11.3%), in schools (2.6%), by private pediatricians (1.6%) and in other settings (0.7%). Focusing on the responses from families whose children attend schools participating in the vaccination program, 21.8% stated that the vaccination was provided in school. CONCLUSION: According to our experience, in Italy, at the moment, only the cooperation between health providers and alternative settings, including schools, may expand flu vaccination coverage. In particular, schools are to be considered a place to inform and reach out to families, useful to increase vaccination coverage.

Characterizing the antigenic evolution of pandemic influenza A (H1N1) pdm09 from 2009 to 2023.

The H1N1pdm09 virus has been a persistent threat to public health since the 2009 pandemic. Particularly, since the relaxation of COVID-19 pandemic mitigation measures, the influenza virus and SARS-CoV-2 have been concurrently prevalent worldwide. To determine the antigenic evolution pattern of H1N1pdm09 and develop preventive countermeasures, we collected influenza sequence data and immunological data to establish a new antigenic evolution analysis framework. A machine learning model (XGBoost, accuracy = 0.86, area under the receiver operating characteristic curve = 0.89) was constructed using epitopes, physicochemical properties, receptor binding sites, and glycosylation sites as features to predict the antigenic similarity relationships between influenza strains. An antigenic correlation network was constructed, and the Markov clustering algorithm was used to identify antigenic clusters. Subsequently, the antigenic evolution pattern of H1N1pdm09 was analyzed at the global and regional scales across three continents. We found that H1N1pdm09 evolved into around five antigenic clusters between 2009 and 2023 and that their antigenic evolution trajectories were characterized by cocirculation of multiple clusters, low-level persistence of former dominant clusters, and local heterogeneity of cluster circulations. Furthermore, compared with the seasonal H1N1 virus, the potential cluster-transition determining sites of H1N1pdm09 were restricted to epitopes Sa and Sb. This study demonstrated the effectiveness of machine learning methods for characterizing antigenic evolution of viruses, developed a specific model to rapidly identify H1N1pdm09 antigenic variants, and elucidated their evolutionary patterns. Our findings may provide valuable support for the implementation of effective surveillance strategies and targeted prevention efforts to mitigate the impact of H1N1pdm09.

Routine Vaccination During Pregnancy Among People Living With HIV in the United States.

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.

Comparative Effectiveness of Baloxavir Marboxil and Oseltamivir Treatment in Reducing Household Transmission of Influenza: A Post Hoc Analysis of the BLOCKSTONE Trial.

BACKGROUND: The transmission of influenza virus in households, especially by children, is a major route of infection. Prior studies suggest that timely antiviral treatment of ill cases may reduce infection in household contacts. The aim of the study was to compare the effects of oseltamivir (OTV) and baloxavir marboxil (BXM) treatment of index cases on the secondary attack rate (SAR) of influenza within household. METHODS: A post hoc analysis was done in BLOCKSTONE trial-a placebo-controlled, double-blinded post-exposure prophylaxis of BXM. Data were derived from the laboratory-confirmed index cases' household contacts who received placebo in the trial and also from household members who did not participate in the trial but completed illness questionnaires. To assess the SAR of household members, multivariate analyses adjusted for factors including age, vaccination status, and household size were performed and compared between contacts of index cases treated with BXM or OTV. RESULTS: In total, 185 index cases (116 treated with BXM and 69 treated with OTV) and 410 household contacts (201 from trial, 209 by questionnaire) were included. The Poisson regression modeling showed that the SAR in household contacts of index cases treated with BXM and OTV was 10.8% and 18.5%, respectively; the adjusted relative reduction in SAR was 41.8% (95% confidence interval: 1.0%-65.7%, p = 0.0456) greater with BXM than OTV. Similar reductions were found in contacts from the trial and those included by questionnaire. CONCLUSION: BXM treatment of index cases appeared to result in a greater reduction in secondary household transmission than OTV treatment.

Public health and economic benefits of seasonal influenza vaccination in risk groups in France, Italy, Spain and the UK: state of play and perspectives.

BACKGROUND: Seasonal influenza epidemics have a substantial public health and economic burden, which can be alleviated through vaccination. The World Health Organization (WHO) recommends a 75% vaccination coverage rate (VCR) in: older adults (aged ≥ 65 years), individuals with chronic conditions, pregnant women, children aged 6-24 months and healthcare workers. However, no European country achieves this target in all risk groups. In this study, potential public health and economic benefits achieved by reaching 75% influenza VCR was estimated in risk groups across four European countries: France, Italy, Spain, and the UK. METHODS: A static epidemiological model was used to estimate the averted public health and economic burden of increasing the 2021/2022 season VCR to 75%, using the efficacy data of standard-dose quadrivalent influenza vaccine. For each country and risk group, the most recent data on population size, VCR, pre-pandemic influenza epidemiology, direct medical costs and absenteeism were identified through a systematic literature review, supplemented by manual searching. Outcomes were: averted influenza cases, general practitioner (GP) visits, hospitalisations, case fatalities, number of days of work lost, direct medical costs and absenteeism-related costs. RESULTS: As of the 2021/2022 season, the UK achieved the highest weighted VCR across risk groups (65%), followed by Spain (47%), France (44%) and Italy (44%). Based on modelling, the 2021/2022 VCR prevented an estimated 1.9 million influenza cases, avoiding 375,200 GP visits, 73,200 hospitalisations and 38,400 deaths. To achieve the WHO 75% VCR target, an additional 24 million at-risk individuals would need to be vaccinated, most of which being older adults and patients with chronic conditions. It was estimated that this could avoid a further 918,200 influenza cases, 332,000 GP visits, 16,300 hospitalisations and 6,300 deaths across the four countries, with older adults accounting for 52% of hospitalisations and 80% of deaths. An additional €84 million in direct medical costs and €79 million in absenteeism costs would be saved in total, with most economic benefits delivered in France. CONCLUSIONS: Older adults represent most vaccine-preventable influenza cases and deaths, followed by individuals with chronic conditions. Health authorities should prioritise vaccinating these populations for maximum public health and economic benefits.

Vaccination with antigenically complex hemagglutinin mixtures confers broad protection from influenza disease.

Current seasonal influenza virus vaccines induce responses primarily against immunodominant but highly plastic epitopes in the globular head of the hemagglutinin (HA) glycoprotein. Because of viral antigenic drift at these sites, vaccines need to be updated and readministered annually. To increase the breadth of influenza vaccine-mediated protection, we developed an antigenically complex mixture of recombinant HAs designed to redirect immune responses to more conserved domains of the protein. Vaccine-induced antibodies were disproportionally redistributed to the more conserved stalk of the HA without hindering, and in some cases improving, antibody responses against the head domain. These improved responses led to increased protection against homologous and heterologous viral challenges in both mice and ferrets compared with conventional vaccine approaches. Thus, antigenically complex protein mixtures can at least partially overcome HA head domain antigenic immunodominance and may represent a step toward a more universal influenza vaccine.

Trivalent mRNA vaccine-candidate against seasonal flu with cross-specific humoral immune response.

Seasonal influenza remains a serious global health problem, leading to high mortality rates among the elderly and individuals with comorbidities. Vaccination is generally accepted as the most effective strategy for influenza prevention. While current influenza vaccines are effective, they still have limitations, including narrow specificity for certain serological variants, which may result in a mismatch between vaccine antigens and circulating strains. Additionally, the rapid variability of the virus poses challenges in providing extended protection beyond a single season. Therefore, mRNA technology is particularly promising for influenza prevention, as it enables the rapid development of multivalent vaccines and allows for quick updates of their antigenic composition. mRNA vaccines have already proven successful in preventing COVID-19 by eliciting rapid cellular and humoral immune responses. In this study, we present the development of a trivalent mRNA vaccine candidate, evaluate its immunogenicity using the hemagglutination inhibition assay, ELISA, and assess its efficacy in animals. We demonstrate the higher immunogenicity of the mRNA vaccine candidate compared to the inactivated split influenza vaccine and its enhanced ability to generate a cross-specific humoral immune response. These findings highlight the potential mRNA technology in overcoming current limitations of influenza vaccines and hold promise for ensuring greater efficacy in preventing seasonal influenza outbreaks.

Enhancing vaccination uptake through community engagement: evidence from China.

With growing recognition of the importance of community engagement in addressing public health challenges, its role in promoting healthy behaviors and preventing infectious diseases has gained attention. However, vaccination coverage remains a significant concern in many developing countries. While previous studies have linked community engagement to positive health outcomes, there is a gap in understanding its influence on individual vaccination choices, particularly in the context of developing countries. Utilizing data from the 2021 Chinese General Social Survey (CGSS), this study examines the impact of community engagement on COVID-19 and flu vaccination uptake among 7281 individuals. Community engagement, measured by community vaccination notifications, serves as the key independent variable. The study employs Ordinary Least Squares (OLS) regression and Propensity Score Matching (PSM) methods to analyze the relationship between community engagement and vaccination behavior. The analysis reveals a positive association between community engagement and vaccination rates. Specifically, individuals receiving notifications were more likely to get the COVID-19 vaccine compared to non-recipients (vaccination rates: 100% vs. 53.3%), and flu vaccination rates were also significantly higher among those notified (2.7% vs. 1.9%). Mechanism analysis suggests that individuals receiving community notifications are more aware of the benefits of vaccination, leading to higher vaccination rates among this group. This study underscores the effectiveness of community engagement strategies in promoting positive vaccination behavior among individuals in China. By enhancing awareness and trust in immunization, community engagement initiatives play a crucial role in shaping health behaviors and improving vaccination uptake. These findings emphasize the importance of integrating community engagement approaches into public health interventions to address vaccination challenges.