Adult Vaccination Research Articles

Relative Effectiveness of High-Dose vs. Standard-Dose Quadrivalent Influenza Vaccine in Older Adults with Cardiovascular Disease: A Prespecified Analysis of the DANFLU-1 Randomized Clinical Trial.

Background: Influenza vaccination reduces the risk of adverse outcomes in patients with cardiovascular disease (CVD). We sought to evaluate whether the presence of CVD modified the relative effectiveness of high-dose (QIV-HD) vs. standard-dose (QIV-SD) quadrivalent influenza vaccine in this prespecified analysis of the DANFLU-1 trial. Methods: DANFLU-1 was a pragmatic, open-label, randomized feasibility trial of QIV-HD vs. QIV-SD in adults aged 65-79 years during the 2021/2022 influenza season in Denmark. Vaccines were allocated in a 1:1 ratio. Baseline and follow-up data regarding diagnoses and mortality were obtained from Danish national registers. The trial is registered at Clinicaltrials.gov: NCT05048589. The CVDs assessed included heart failure (HF), ischemic heart disease (IHD), atrial fibrillation, and a combined group denoted "chronic CVD" consisting of the aforementioned diseases, among others. Prespecified outcomes included hospitalizations for pneumonia or influenza, respiratory disease, CVD, cardiorespiratory disease, all-cause hospitalizations, and mortality. Effect modification was tested using interaction terms. Results: The final study population included 12,477 participants (mean age 71.7±3.9 years, 5,877 (47.1%) female), of whom 2,540 (20.4%) had chronic CVD. QIV-HD vs. QIV-SD was associated with a lower incidence of hospitalizations for pneumonia or influenza (IRR 0.30 (95%-CI 0.14-0.64)) and all-cause mortality (IRR 0.51 (0.30-0.86)) regardless of chronic CVD (p for interaction=0.57 and 0.49, respectively). The relative effectiveness of QIV-HD vs. QIV-SD against all-cause hospitalizations was modified in participants with chronic CVD (Overall: IRR 0.87 (0.76-0.99); no chronic CVD: 0.79 (0.67-0.92); chronic CVD: 1.11 (0.88-1.39); p for interaction=0.026). No other effect modification was observed by the presence of chronic CVD, HF, IHD, or atrial fibrillation. Conclusions: The relative effectiveness of QIV-HD vs. QIV-SD was consistent against hospitalizations for pneumonia or influenza and all-cause mortality regardless of chronic CVD. However, the relative effectiveness against all-cause hospitalizations was modified by the presence of chronic CVD. These results should be considered hypothesis-generating.

The impact of COVID-19 pandemic on recommended adult vaccination in the elderly: A hospital-based study

ÖZET Amaç: COVİD-19 salgınıyla birlikte tüm dünyada ve Türkiye'de önemli değişiklikler meydana geldi. Önerilen yetişkin aşılama uygulamaları da bunlardan biridir. Bu çalışma, COVID-19 salgını öncesi ve sonrası yetişkinlerde aşılama oranlarını ve farkındalıklarını karşılaştırmayı amaçlamaktadır. Materyal ve Metodlar: Yanıt verenlere sosyodemografik özellikler (yaş, cinsiyet, medeni durum, eğitim durumu, yandaş hastalıklar), yetişkinlikte yapılan aşılar, pandemi öncesi ve pandemi sırasında aşı yaptırma ve aşılardan kaçınma nedenleri soruldu. Sonuçlar tüm yazarların izni alınarak aynı hastanenin aynı polikliniğinde 31.01.2017- 01.06.2017 tarihleri arasında gerçekleştirilen çalışmanın verileriyle karşılaştırıldı. Bulgular: Pnömokok (%9,9 vs %56,5) (p<0,001), influenza (%33,9 vs %47,7) (p=0,004), tetanoz (%1,3 vs %20,7) (p<0,001) ve hepatit B (%0,7 vs %4,8) (p=0,04) olduğu gözlendi. Aşılanma oranlarında pandemi öncesi döneme göre pandemi döneminde anlamlı artış görüldü. Sonuç: Erişkin aşı kapsamı yetersiz olmakla birlikte, pandemiyle birlikte erişkinlerde özellikle pnömokok aşı kapsamı artmıştır. Bu artışta geleneksel ve sosyal medyanın önemli bir rolü olduğu değerlendirildi. Anahtar kelimeler: Aşılama, aşı karşıtlığı, aşı takvimi, COVID-19 pandemisi, geleneksel medya, sosyal medya

Addressing Vaccination Gaps through Student-Led Initiatives: A Study of Stanford Vax Crew's Impact

Background: Although vaccines are critical to disease prevention, substantial gaps persist in adult vaccination coverage in the United States due, in part, to material and social barriers. Farmworkers face unique challenges to accessing vaccination services, such as migratory residence, immigration status, low levels of insurance, and geographic distance from clinics, many of which were exacerbated during the coronavirus disease 2019 (COVID-19) pandemic. Student-driven, community-focused programs offer a potential mechanism to enhance vaccine equity. Stanford Vax Crew is a student-led organization that partners with community organizations to host pop-up vaccine clinics, which aim to (1) address the material barriers that impact vaccination status, (2) establish trust in vaccine services, and (3) equip future medical professionals with skills to engage in community health initiatives. Methods: This paper describes the strategies used by the organization to reach surrounding communities with vaccines, especially agricultural workers. It assesses the reach of the program through analysis of demographic data collected at pop-up clinics. Results: From August 2021 to March 2023, the majority of COVID-19 vaccine recipients were middle-aged adults (61%) of Hispanic ethnicity (82%) working in the agricultural, forestry, or fishing industries (58%). In total, 1377 COVID-19 vaccines were administered by Stanford Vax Crew. Conclusions: Findings suggest that Stanford Vax Crew's partnerships with diverse institutions helped facilitate access and build trust, thereby enhancing vaccine uptake. Partnership with agricultural employers and community-based organizations targeted farmworkers, which enabled the group to host clinics on farms immediately before and after work hours, which proved especially effective for reaching agricultural workers.

Long-term safety and effectiveness of mRNA-1273 vaccine in adults: COVE trial open-label and booster phases

Primary vaccination with mRNA-1273 (100-µg) was safe and efficacious at preventing coronavirus disease 2019 (COVID-19) in the previously reported, blinded Part A of the phase 3 Coronavirus Efficacy (COVE; NCT04470427) trial in adults (≥18 years) across 99 U.S. sites. The open-label (Parts B and C) primary objectives were evaluation of long-term safety and effectiveness of primary vaccination plus a 50-µg booster dose; immunogenicity was a secondary objective. Of 29,035 open-label participants, 19,609 received boosters (mRNA-1273 [n = 9647]; placebo-mRNA-1273 [n = 9952]; placebo [n = 10] groups). Booster safety was consistent with that reported for primary vaccination. Incidences of COVID-19 and severe COVID-19 were higher during the Omicron BA.1 than Delta variant waves and boosting versus non-boosting was associated with a significant, 47.0% (95% CI : 39.0-53.9%) reduction of Omicron BA.1 incidence (24.6 [23.4 − 25.8] vs 46.4 [40.6 − 52.7]/1000 person-months). In an exploratory Cox regression model adjusted for time-varying covariates, a longer median interval between primary vaccination and boosting (mRNA-1273 [13 months] vs placebo-mRNA-1273 [8 months]) was associated with significantly lower, COVID-19 risk (24.0% [16.0% − 32.0%]) during Omicron BA.1 predominance. Boosting elicited greater immune responses against SARS-CoV-2 than primary vaccination, irrespective of prior SARS-CoV-2 infection. Primary vaccination and boosting with mRNA-1273 demonstrated acceptable safety, effectiveness and immunogenicity against COVID-19, including emergent variants.

CLOVER: A Phase 3 Randomized Trial Investigating the Efficacy and Safety of a Detoxified Toxin A/B Vaccine in Adults 50 Years and Older at Increased Risk of Clostridioides difficile Infection.

Clostridioides difficile infection (CDI) causes substantial mortality and healthcare burden. We assessed the detoxified toxin-A/B PF-06425090 vaccine for primary CDI prevention. This phase 3 observer-blinded study randomized (1:1) ≥50-year-olds at increased CDI risk (N=17,535) to receive 3 PF-06425090 or placebo doses (0,1,6-months). Primary endpoints were first CDI episode (≥3 unformed stools within 24 hours; central laboratory-confirmed toxin A/B positive) ≥14 days post-dose 3 (PD3; first primary) and post-dose 2 (PD2; second primary). CDI duration, need for CDI-related medical attention (secondary endpoints), and antibiotic use (post hoc analysis) PD3 were evaluated. Tolerability/safety was assessed. The primary endpoint was not met (17 PF-06425090 and 25 placebo recipients had first CDI episode ≥14 days PD3 [vaccine efficacy (VE)=31.0% (96.4%CI: -38.7%-66.6%)]; 24 PF-06425090 and 34 placebo recipients had first CDI episode ≥14 days PD2 [VE=28.6% (-28.4%-61.0%)]). Median CDI duration was lower with PF-06425090 (1 day) versus placebo (4 days; 2-sided nominal P=0.02). Of participants with first CDI episode, 0 PF-06425090 and 11 placebo recipients sought CDI-related medical attention (post hoc analysis estimated VE=100% [95%CI: 59.6%-100.0%]) and 0 PF-06425090 and 10 placebo recipients required antibiotic treatment (VE=100% [54.8%-100.0%]). Local reactions were more frequent in PF-06425090 recipients and systemic events were generally similar between groups; most were mild-to-moderate. AE rates were similar between groups. Three PF-06425090 doses were safe and well-tolerated. Although the primary endpoint was not met, PF-06425090 reduced symptom duration, CDI requiring medical attention, and CDI-directed antibiotic treatment, highlighting its potential to reduce CDI-associated healthcare burden. NCT03090191.

Immunogenicity and Safety of an Inactivated Quadrivalent Influenza Vaccine Administered Concomitantly with a 23-Valent Pneumococcal Polysaccharide Vaccine in Adults Aged 60 Years and Older.

The inactivated quadrivalent influenza vaccine (IIV4) and the 23-valent pneumococcal polysaccharide vaccine (PPSV23) have been administered for years and could be administered concomitantly if necessary. However, the immunogenicity and safety of the concomitant administration of these two vaccines have not been well documented, especially in the Chinese population. In this study, 480 participants aged 60 years and older were randomly assigned to the concomitant administration group (C group) or the separate administration group (S group) to receive IIV4 and PPSV23 either concomitantly or separately. Blood samples were collected before and 28 days after each vaccination. The antibodies against four influenza virus strains and twenty-three pneumococcus serotypes were tested. The results showed that the geometric mean titer (GMT) ratios (C group to S group) for the four influenza strains ranged from 0.72 to 0.95, with the lower limits of the 95% confidence intervals (CIs) ranging from 0.51 to 0.75, and the geometric mean concentration (GMC) ratios for the 23 pneumococcal serotypes ranged from 0.80 to 1.00, with the lower limits of 95% CIs ranging from 0.67 to 0.86. All values met the predefined criteria for non-inferiority. The incidence of adverse events was 0.63% in the C group and 1.56% in the S group. No serious adverse events were observed. In conclusion, the immunogenicity of the concomitant administration of IIV4 and PPSV23 was non-inferior to that of the separate administration, and the safety profile was favorable in adults aged 60 years and older in China.

Mapping the existing body of knowledge on new and repurposed TB vaccine implementation: A scoping review.

There is global consensus on the urgent need for a safe and effective TB vaccine for adults and adolescents to improve global TB control, and encouragingly, several promising candidates have advanced to late-stage trials. Significant gaps remain in understanding the critical factors that will facilitate the successful implementation of new and repurposed TB vaccines in low- and middle-income countries (LMICs), once available. By synthesizing the existing body of knowledge, this review offers comprehensive insights into the current state of research on implementation of these adult and adolescent vaccines. This review explores four key dimensions: (1) epidemiological impact, (2) costing, cost-effectiveness, and/or economic impact, (3) acceptability, and the (4) feasibility of implementation; this includes implementation strategies of target populations, and health system capabilities. Results indicate that current research primarily consists of epidemiological and costing/cost-effectiveness/economic studies in India, China, and South Africa, mainly modelling with M72/AS01, BCG revaccination, and hypothetical vaccines. Varying endpoints, vaccine efficacies, and vaccination coverages were used. Globally, new, and repurposed TB vaccines are estimated to save millions of lives. Economically, these vaccines also demonstrate promise with expected cost-effectiveness in most countries. Projected outcomes were dependent on vaccine characteristics, target population, implementation strategy, timing of roll out, TB burden/country context, and vaccination coverage. Potential barriers for vaccine acceptability included TB-related stigma, need for a second dose, and cost, while low pricing, community and civil society engagement and heightened public TB awareness were potential enablers in China, India, and South Africa. Potential implementation strategies considered spanned from mass campaigns to integration within existing vaccine programs and the primary target group studied was the general population, and adults and adolescents. In conclusion, future research must have broader geographical representations to better understand what is needed to inform tailored vaccine programs to accommodate diverse country contexts and population groups to achieve optimal implementation and impact. Furthermore, this review underscores the scarcity of research on acceptability of new and repurposed TB vaccines and their delivery among potential beneficiaries, the most promising implementation strategies, and the health system capabilities necessary for implementation. The absence of this knowledge in these areas emphasizes the crucial need for future research to ensure effective TB vaccine implementation in high burden settings worldwide.

Influenza Vaccination in Adults in the United States with COPD before and after the COVID-19 Pandemic (2017-2022): A Multi-Year Cross-Sectional Study.

There is limited literature regarding seasonal influenza vaccination (SIV) among those with a history of chronic obstructive pulmonary disease (HCOPD) prior to the COVID-19 pandemic, and no information on the topic assessing the years following the pandemic. This cross-sectional study used the Behavioral Risk Factor Surveillance Survey (BRFSS) data from the years 2017 to 2022 (n = 822,783 adults ages 50-79 years; 50.64% males). The exposure was a HCOPD, and the outcome was SIV within the past year. Weighted and adjusted logistic regression models were conducted overall and by the significant effect modifiers: smoking status, sex, and year. Having an HCOPD significantly increases the weighted adjusted odds (WAO) of SIV when compared to not having an HCOPD overall and by smoking status, sex, and year. For 2017 through 2022, among all current, former, and never smokers with an HCOPD, the WAO of SIV were: 1.36 (1.28, 1.45), 1.35 (1.27, 1.43), and 1.18 (1.09, 1.27), respectively. Among males with an HCOPD who were current, former, and never smokers, the WAO of SIV were: 1.35 (1.23, 1.48), 1.45 (1.33, 1.58), and 1.23 (1.05, 1.44), respectively. Among females with an HCOPD who were current, former, and never smokers, the WAO of SIV were: 1.31 (1.20, 1.43), 1.24 (1.15, 1.35), and 1.13 (1.04, 1.23), respectively. Study findings suggest males had significantly greater WAO ratios of receiving SIV than females in 2020 and 2022, during and after the COVID-19 pandemic. More specifically, males with an HCOPD who were former smokers had significantly greater WAOR of receiving SIV than females in 2020 and 2022. Understanding the potential barriers to SIV receipt by smoking status and sex, especially during a pandemic, and especially for individuals impacted by an HCOPD, is essential for better health interventions in times of a national crisis such as a pandemic. Additionally, SIV receipt is low among those with an HCOPD, and efforts should be made to improve this.

Expert recommendations on hepatitis B vaccination in adults

In order to achieve the target of eliminating viral hepatitis as a public health threat by 2030 and to prioritize the role of hepatitis B vaccination in reducing new hepatitis B virus infections, the Chinese Preventive Medicine Association commissioned experts to develop the Expert Recommendations on Hepatitis B Vaccination in Adults to scientifically guide adult hepatitis B vaccination,build the herd immunity in population, and reduce the hepatitis B virus infection rate and incidence of hepatitis B.

Indirect impact of childhood 13-valent pneumococcal conjugate vaccine (PCV13) in Canadian older adults: a Canadian Immunization Research Network (CIRN) retrospective observational study

Background13-valent pneumococcal conjugate vaccine (PCV13) has been part of publicly funded childhood immunisation programmes in Ontario and British Columbia (BC) since 2010. We assessed the indirect impact of infant PCV13...

Use of Respiratory Syncytial Virus Vaccines in Adults Aged ≥60 Years: Updated Recommendations of the Advisory Committee on Immunization Practices - United States, 2024.

Respiratory syncytial virus (RSV) is a major cause of respiratory illness and hospitalization in older adults during fall and winter in the United States. The 2023-2024 RSV season was the first during which RSV vaccination was recommended for U.S. adults aged ≥60 years, using shared clinical decision-making. On June 26, 2024, the Advisory Committee on Immunization Practices voted to update this recommendation as follows: a single dose of any Food and Drug Administration-approved RSV vaccine (Arexvy [GSK]; Abrysvo [Pfizer]; or mResvia [Moderna]) is now recommended for all adults aged ≥75 years and for adults aged 60-74 years who are at increased risk for severe RSV disease. Adults who have previously received RSV vaccine should not receive another dose. This report summarizes the evidence considered for these updated recommendations, including postlicensure data on vaccine effectiveness and safety, and provides clinical guidance for the use of RSV vaccines in adults aged ≥60 years. These updated recommendations are intended to maximize RSV vaccination coverage among persons most likely to benefit, by clarifying who is at highest risk and by reducing implementation barriers associated with the previous shared clinical decision-making recommendation. Continued postlicensure monitoring will guide future recommendations.

Another (and comparable) RSV vaccine for older adults

Another (and comparable) RSV vaccine for older adults

Systematic Review of Individual Patient Data COVID-19 Infection and Vaccination–Associated Thrombotic Microangiopathy

Sporadic cases of atypical hemolytic uremic syndrome (aHUS) have been described in the literature in association with COVID-19 infection and vaccination in adults and pediatric patients. The exact mechanisms underlying COVID-19-associated thrombotic microangiopathies (TMAs) remain incompletely understood. Herein, we present a detailed meta-analysis of the clinical characteristics, outcomes, and management strategies of COVID-19-associated aHUS and thrombotic thrombocytopenic purpura (TTP). This study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses updated guidelines. PubMed was utilized for searching for case reports and series. Adverse outcome at last follow-up was defined as estimated glomerular filtration rate< 30 ml/min per 1.73 m2 (patients with aHUS), no remission with therapy, or patient death. Data were analyzed using Wilcoxon rank and Chi-square tests. Our analysis cohort included 118 studies reporting on 170 patients. These included 84 cases of aHUS and 86 cases of TTP resulting from COVID-19 infection (n= 92) or vaccination (n= 78). Significantly more cases of aHUS were reported after infection (n= 65) than immunization (n= 19), compared to TTP, where the reverse was true (n= 27 and n= 59, respectively; P< 0.001). In patients with aHUS with stage 3 acute kidney injury (AKI), requirement of kidney replacement therapy (KRT) was seen in three-fourths of the cohort for a median of 15. In patients with TTP, severe COVID-19 infection (P= 0.04) predicted nonremission or death at last follow-up. Administration of i.v., rituximab and caplacizumab were protective (P= 0.03 and P= 0.06, respectively). Immune TTP (iTTP) was reported more often than HUS following mRNA vaccines (81% vs. 58%; P= 0.06). COVID-19 infection and vaccination are a potential trigger for onset or relapse of aHUS and TTP, especially in patients who are not on maintenance complement inhibitors or immunosuppression.

Integrating youth participatory action research and health communication to inform youth and young adult covid-19 vaccine communication research.

COVID-19 vaccination rates remain lower among adolescents compared with adults. Youth participatory action research (YPAR) offers opportunities to inform youth vaccine communication at the local and population level. However, few studies have integrated systematic health communication research with YPAR. In the current study, a diverse team of paid high school interns, undergraduate student mentors and communication researchers in West Philadelphia YPAR programs developed a theory-informed communication survey to measure teen COVID-19 vaccine beliefs, information sources and behavior. The survey was distributed locally and informed youth-created vaccine campaign messages. In addition, YPAR-derived survey measures complimented a qualitative online elicitation survey with US young adults. Responses were coded using inductive content analysis, informing measures for a subsequent population-level study of young adults. This research followed protocols approved by an Institutional Review Board. Applying a YPAR framework elevated youth voices in the study development process. Communication theory and methods aided the development of survey studies to advance both local YPAR program objectives and population-level research. Future implications are discussed.

Knowledge, attitude and practices of adult vaccine among the staff of vaccination units in Shandong Province

In order to understand the knowledge, attitude and practice (KAP) of vaccination against influenza, pneumonia, human papillomavirus (HPV), herpes zoster (HZ), COVID-19, and hepatitis B among staff of vaccination units in Shandong Province, a sample survey was conducted among 797 staffs of adult vaccination units in 12 counties (cities and districts) of Shandong Province from August to September 2022. The results showed that the respondents had the highest total score of knowledge and attitude for the COVID-19 vaccine, with the M (Q1, Q3) of 23 (20, 25) and 10 (10, 10), respectively, and had the lowest score of knowledge and attitude for the herpes zoster vaccine, with the M (Q1, Q3) of 19 (15, 22) and 8 (8, 10), respectively. The vaccine-related knowledge point"vaccine applicable population"had the highest score, with the M (Q1,Q3) of 26 (23, 30). The "contraindications/adverse reactions" and "adverse reaction management" had the lowest score, with the M (Q1, Q3) of 24 (20, 29) and 24 (20, 28), respectively. About 89.71% of respondents received one adult vaccine within two years at least. The principal driver for vaccination of 53.58% of recipients was their understanding of vaccines, which was"it was necessary to receive the vaccine". About 66.00% of respondents who had not received any adult vaccine in the past two years had insufficient awareness of the necessity of vaccination and believed that they were in good health and did not need to receive it. In summary, the staff of adult vaccination units in Shandong Province have a poor understanding of the herpes zoster vaccine in terms of vaccines and a relatively poor understanding of"contraindications/adverse reaction and management"in adult vaccination knowledge points.

Impact of COVID-19 on vaccine confidence and uptake: A systematic literature review

ABSTRACT During the coronavirus disease 2019 (COVID-19) pandemic, scheduled vaccinations were postponed, mass vaccination programmes were suspended and opportunities for healthcare workers to administer vaccines ad hoc decreased. The aims of this systematic literature review were to determine the impact of the COVID-19 pandemic on vaccine confidence, intent and uptake in preexisting routine childhood or adult vaccination programmes, and to identify factors associated with changes in acceptance, intent and uptake of preexisting vaccines. Medline and Embase were searched for studies in Australia, Brazil, Canada, China, Japan, the USA, and European countries, published between 1 January 2021 and 4 August 2022. A complementary gray literature search was conducted between 11 and 13 October 2022, and supplemented with additional gray research in October 2023. In total, 54 citations were included in the review. Study design and geography were heterogeneous. The number of adults who received or intended to receive an influenza or pneumococcal vaccine was higher during the pandemic than in previous seasons (n = 28 studies). In addition, increased acceptance of adult vaccinations was observed during 2020–21 compared with 2019–20 (n = 12 studies). The rates of childhood vaccinations decreased during the COVID-19 pandemic across several countries (n = 11 studies). Factors associated with changes in intention to receive a vaccination, or uptake of influenza vaccine, included previous vaccination, older age, higher perceived risk of contracting COVID-19, anxiety regarding the pandemic and fear of contracting COVID-19. Acceptance and uptake of influenza and pneumococcal vaccines generally increased after onset of the COVID-19 pandemic.

Noninferior Immunogenicity and Consistent Safety of Respiratory Syncytial Virus Prefusion F Protein Vaccine in Adults 50-59 Years Compared to ≥60 Years of Age.

The adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine (RSVPreF3 OA) is approved in adults aged ≥60 years. We evaluated RSVPreF3 OA immunogenicity and safety in adults aged 50-59 years without or with increased risk for RSV disease due to specific chronic medical conditions. This observer-blind, phase 3, noninferiority trial included adults aged 50-59 years, stratified into 2 subcohorts: those with and those without predefined, stable, chronic medical conditions leading to an increased risk for RSV disease. Participants in both subcohorts were randomized 2:1 to receive RSVPreF3 OA or placebo. A control group of adults aged ≥60 years received RSVPreF3 OA. Primary outcomes were RSV-A and RSV-B neutralization titers (geometric mean titer ratios and sero-response rate differences) 1 month post-vaccination in 50-59-year-olds versus ≥60-year-olds. Cell-mediated immunity and safety were also assessed. The exposed population included 1152 participants aged 50-59 years and 381 participants aged ≥60 years. RSVPreF3 OA was immunologically noninferior in 50-59-year-olds versus ≥60-year-olds; noninferiority criteria were met for RSV-A and RSV-B neutralization titers in those with and those without increased risk for RSV disease. Frequencies of RSVPreF3-specific polyfunctional CD4+ T cells increased substantially from pre- to 1 month post-vaccination. Most solicited adverse events had mild-to-moderate intensity and were transient. Unsolicited and serious adverse event rates were similar in all groups. RSVPreF3 OA was immunologically noninferior in 50-59-year-olds compared to ≥60-year-olds, in whom efficacy was previously demonstrated. The safety profile in 50-59-year-olds was consistent with that in ≥60-year-olds. ClinicalTrials.gov: NCT05590403.

Safety and Immunogenicity of Respiratory Syncytial Virus Prefusion F Protein Vaccine when Co-administered with Adjuvanted Seasonal Quadrivalent Influenza Vaccine in Older Adults: A Phase 3 Randomized Trial.

We evaluated co-administration of adjuvanted seasonal quadrivalent influenza vaccine (FLU-aQIV) and respiratory syncytial virus (RSV) prefusion F protein-based vaccine (RSVPreF3 OA) in ≥65-year-olds. This phase 3, open-label trial randomized ≥65-year-olds to receive FLU-aQIV and RSVPreF3 OA concomitantly (Co-Ad) or sequentially, 1 month apart (Control). Primary objectives were to demonstrate the non-inferiority of FLU-aQIV and RSVPreF3 OA co-administration versus sequential administration in terms of hemagglutination inhibition (HI) titers for each FLU-aQIV strain and RSV-A and RSV-B neutralization titers, 1 month post-vaccination. Reactogenicity and safety were also assessed. Overall, 1045 participants were vaccinated (Co-Ad: 523; Control: 522). Non-inferiority of FLU-aQIV and RSVPreF3 OA co-administration versus sequential administration was demonstrated in terms of HI titers for the A/Victoria(H1N1), B/Victoria, and B/Yamagata influenza strains and RSV-A neutralization titers (upper limits [ULs] of 95% confidence intervals [CIs] for adjusted geometric mean titer [GMT] ratios [Control/Co-Ad] ≤1.50) but not for A/Darwin(H3N2) HI titers (95% CI UL = 1.53). The immune response to A/Darwin(H3N2) was further assessed post-hoc using a microneutralization assay; the post-vaccination adjusted GMT ratio (Control/Co-Ad) was 1.23 (95% CI: 1.06-1.42, ie, UL ≤1.50), suggesting an adequate immune response to A/Darwin(H3N2) following co-administration. RSV-B neutralization titers were comparable between groups (95% CI UL for adjusted GMT ratio ≤1.50). Solicited adverse events were mostly mild or moderate and transient; unsolicited and serious adverse event rates were balanced between groups. Adjuvanted FLU-aQIV and RSVPreF3 OA had acceptable reactogenicity/safety profiles when co-administered in ≥65-year-olds, without clinically relevant interference with the immune responses to either vaccine. NCT05568797.

The relative effectiveness of a high-dose quadrivalent influenza vaccine versus standard-dose quadrivalent influenza vaccines in older adults in France: a retrospective cohort study during the 2021–2022 influenza season

ObjectivesHigh-dose quadrivalent influenza vaccine (HD-QIV) was introduced during the 2021/2022 influenza season in France for adults aged ≥65 years as an alternative to standard-dose quadrivalent influenza vaccine (SD-QIV). The aim of this study is to estimate the relative vaccine effectiveness of HD-QIV vs. SD-QIV against influenza-related hospitalizations in France. MethodsCommunity-dwelling individuals aged ≥65 years with reimbursed influenza vaccine claims during the 2021/2022 influenza season were included in the French national health insurance database. Individuals were followed up from vaccination day to 30 June 2022, nursing home admission or death date. Baseline socio-demographic and health characteristics were identified from medical records over the five previous years. Hospitalizations for influenza and other causes were recorded from 14 days after vaccination until the end of follow-up. HD-QIV and SD-QIV vaccinees were matched using 1:4 propensity score matching with an exact constraint on age group, sex, week of vaccination, and region. Incidence rate ratios were estimated using zero-inflated Poisson or zero-inflated negative binomial regression models. ResultsWe matched 405 385 HD-QIV to 1 621 540 SD-QIV vaccinees. HD-QIV was associated with a 23.3% (95% CI, 8.4–35.8) lower rate of influenza hospitalizations compared with SD-QIV (69.5/100 000 person years vs. 90.5/100 000 person years). Post-matching, we observed higher rates in the HD-QIV group for hospitalizations non-specific to influenza and negative control outcomes, suggesting residual confounding by indication. DiscussionHD-QIV was associated with lower influenza-related hospitalization rates vs. SD-QIV, consistent with existing evidence, in the context of high SARS-CoV-2 circulation in France and likely prioritization of HD-QIV for older/more comorbid individuals.

Cellular immune response to a single dose of live attenuated hepatitis a virus vaccine in obese children and adolescents

BackgroundLimited data are currently available regarding the cellular immune response to a live attenuated hepatitis A virus (HAV) vaccine, especially in children with obesity. The objective of this retrospective cohort study was to compare the activation of antigen-specific interferon (IFN)-γ+ T cells in obese children and adolescents with healthy individuals before and after immunization with a single dose of live attenuated HAV vaccine. MethodsBlood samples were obtained from the 2021 study by Dumrisilp et al. investigating the immunogenicity of the live attenuated hepatitis A vaccine in children and young adults. Prior to enrollment, all 212 subjects had never received any HAV vaccine and tested negative for anti-HAV antibodies. The participants were vaccinated with a freeze-dried, live attenuated HAV vaccine of the H2 strain. In this study, we analyzed the stored peripheral blood mononuclear cells (PBMCs) obtained from a subgroup of 30 obese subjects and 30 normal-weight healthy controls of the same age and sex. PBMCs were collected before and 8–9 weeks after HAV vaccination for further analysis. These cells were stimulated with a recombinant antigen derived from HAV-VP3, and the immune response was evaluated using the IFN-γ enzyme-linked immunospot (ELISpot) assay. ResultsThe between-group analysis indicated that the T-cell response of obese participants was comparable to that of normal-weight controls both before and after vaccination. The change in IFN-γ production from before to after vaccination in the obese group was not significantly different from that of the control group. Additionally, in the obese group, no correlation was found between IFN-γ production and clinical characteristics such as sex, body mass index, waist circumference, and acanthosis nigricans. ConclusionTesting for cellular immune response provides a comprehensive understanding of the overall immune response to vaccination. This study, the first to explore this significant aspect, suggests that obesity does not affect the short-term cellular immune response to live attenuated HAV vaccination.