Influenza Vaccination In Older Adults Research Articles

Real-World Evidence in Cost-Effectiveness Analysis of Enhanced Influenza Vaccines in Adults ≥ 65 Years of Age: Literature Review and Expert Opinion.

Influenza vaccination can benefit most populations, including adults ≥ 65 years of age, who are at greater risk of influenza-related complications. In many countries, enhanced vaccines, such as adjuvanted, high-dose, and recombinant trivalent/quadrivalent influenza vaccines (aTIV/aQIV, HD-TIV/HD-QIV, and QIVr, respectively), are recommended in older populations to provide higher immunogenicity and increased relative vaccine efficacy/effectiveness (rVE) than standard-dose vaccines. This review explores how efficacy and effectiveness data from randomized controlled trials and real-world evidence (RWE) are used in economic evaluations. Findings from published cost-effectiveness analyses (CEA) on enhanced influenza vaccines for older adults are summarized, and the assumptions and approaches used in these CEA are assessed alongside discussion of the importance of RWE in CEA. Results from many CEA showed that adjuvanted and high-dose enhanced vaccines were cost-effective compared with standard vaccines, and that differences in rVE estimates and acquisition price may drive differences in cost-effectiveness estimates between enhanced vaccines. Overall, RWE and CEA provide clinical and economic rationale for enhanced vaccine use in people ≥ 65 years of age, an at-risk population with substantial burden of disease. Countries that consider RWE when making vaccine recommendations have preferentially recommended aTIV/aQIV, as well as HD-TIV/HD-QIV and QIVr, to protect older individuals.

High-dose influenza vaccine in older adults by age and seasonal characteristics: Systematic review and meta-analysis update

This updated systematic review and meta-analysis of randomized and observational studies published up to April 2023 assessed the relative performance of high-dose inactivated influenza vaccine (HD-IIV) and standard-dose influenza vaccines (SD-IIV) against influenza-associated outcomes in older adults (≥65 years).The analysis included studies conducted over 12 influenza seasons (2009/2010 to 2019/2020, 2021/2022), including over 45 million individuals aged ≥ 65 years, and showed that HD-IIV provided significantly better protection than SD-IIV against influenza-like illness and influenza-related hospitalizations, as well as cardiovascular, cardiorespiratory, and all-cause hospitalizations. Subgroup analyses showed HD-IIV consistently provided better protection than SD-IIV against influenza outcomes across the age range (65+, 75+ 85+ years), and regardless of the predominantly circulating influenza strain and vaccine antigenic match/mismatch.Randomized studies continue to drive high-quality evidence on the effectiveness of high-dose inactivated influenza vaccine relative to SD-IIV against severe influenza outcomes in adults aged ≥ 65 years, supported by observational data.

Cost-Effectiveness of the Use of Adjuvanted Quadrivalent Seasonal Influenza Vaccine in Older Adults in Ireland.

Enhanced vaccines (e.g., containing adjuvants) have shown increased immunogenicity and effectiveness in older adults, who often respond sub-optimally to conventional influenza vaccines. In this study, we evaluated the cost-effectiveness of an inactivated, seasonal, MF59-adjuvanted quadrivalent influenza vaccine (aQIV) for use in adults ≥ 65 years in Ireland. A published dynamic influenza model incorporating social contact, population immunity, and epidemiological data was used to assess the cost-effectiveness of aQIV in adults ≥ 65 years of age compared with a non-adjuvanted QIV. Sensitivity analysis was performed for influenza incidence, relative vaccine effectiveness, excess mortality, and the impact on bed occupancy from co-circulating influenza and COVID-19. The use of aQIV resulted in discounted incremental cost-effectiveness ratios (ICERs) of EUR 2420/quality-adjusted life years (QALYs) and EUR 12,970/QALY from societal and payer perspectives, respectively, both of which are below the cost-effectiveness threshold of EUR 45,000/QALY. Sensitivity analysis showed that aQIV was effective in most scenarios, except when relative vaccine effectiveness compared to QIV was below 3%, and resulted in a modest reduction in excess bed occupancy. The use of aQIV for adults ≥ 65 years old in Ireland was shown to be highly cost-effective from both payer and societal perspectives.

Association of Influenza Vaccination and Dementia Risk: A Meta-Analysis of Cohort Studies.

Dementia is a critical global public health problem. Previous cohort studies have found that influenza vaccination can decrease the risk of dementia. This meta-analysis aimed to systematically examine the relationship between influenza vaccination and dementia risk. We searched PubMed, Embase, Web of Science, ScienceDirect, medRxiv, and bioRxiv for studies investigating dementia risk based on influenza vaccination status, up to September 14, 2022. Relative risks (RRs) and 95% confidence intervals (95% CIs) were pooled in the meta-analysis. Subgroup analyses and sensitivity analyses were conducted as well. Of the 4,087 articles initially reviewed, 6 cohort studies were included in the final meta-analysis, and all eligible studies were at low risk of bias. There were 2,087,195 participants without dementia at baseline (mean age: 61.8-75.5 years, 57.05% males), and 149,804 (7.18%) cases of dementia occurred during 4.00-13.00 years of follow-up. Pooled analysis of adjusted RRs found that influenza vaccination could reduce dementia risk by 31% (RR = 0.69, 95% CI: 0.57-0.83). Subgroup analyses showed that in the study with a mean age of 75-80 years or 75%-100% males, the association was generally weakened compared with studies with a mean age of 60-75 years or 25%-50% males. The results were stable in the sensitivity analyses, and no publication bias was observed. Influenza vaccination in older adults was markedly associated with a decreased risk of dementia. More mechanistic studies and epidemiological studies are needed to clarify the association between influenza vaccination and decreased dementia risk.

Effect of a nationwide intervention of electronic letters with behavioural nudges on influenza vaccination in older adults in Denmark

Worldwide influenza epidemics result in an estimated 3–5 million cases of severe illness, and 290 000–650 000 respiratory deaths annually. 1 WHOInfluenza (seasonal). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)Date accessed: February 19, 2023 Google Scholar Influenza also leads to high costs from direct medical expenses and lost productivity. 2 Putri W Muscatello DJ Stockwell MS Newall AT Economic burden of seasonal influenza in the United States. Vaccine. 2018; 36: 3960-3966 Crossref PubMed Scopus (212) Google Scholar Influenza vaccination is the single most important preventive measure against influenza, and as such is recommended worldwide. 1 WHOInfluenza (seasonal). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)Date accessed: February 19, 2023 Google Scholar Adults aged 65 years or older are at particularly high risk for severe outcomes related to influenza. 1 WHOInfluenza (seasonal). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)Date accessed: February 19, 2023 Google Scholar However, annual vaccination rates of older adults vary globally from less than 10% up to 80%. 3 Organisation for Economic Co-operation and DevelopmentInfluenza vaccination rates. https://data.oecd.org/healthcare/influenza-vaccination-rates.htmDate accessed: February 19, 2023 Google Scholar Electronic nudges to increase influenza vaccination uptake in Denmark: a nationwide, pragmatic, registry-based, randomised implementation trialElectronically delivered letters highlighting potential cardiovascular benefits of influenza vaccination or sent again as a reminder significantly increased vaccination uptake across Denmark. Although the magnitude of effectiveness was modest, the low-touch, inexpensive, and highly scalable nature of these electronic letters might be informative for future public health campaigns. Full-Text PDF

Estimation of vaccination coverage and associated factors in older Mexican adults.

National vaccination programmes recommend the influenza vaccine for older adults, but this population group has the greatest morbidity and mortality from other preventable vaccine diseases. The aim of this article is to estimate the vaccine coverage in adults aged 65years and older and to analyse the factors that could increase or decrease vaccination uptake probability for the three listed vaccines in the national vaccination programme (influenza, tetanus and diphtheria, and pneumococcus) and the full scheme in Mexico. We conducted an analytical cross-sectional study with 2012, 2018, and 2021 rounds from the National Health and Nutrition Survey, in which we calculated the vaccine coverage estimations and performed multivariable logistic regression models to analyse the factors related to vaccine uptake. Tetanus and diphtheria vaccines had the greatest coverage estimation in all years (59-71%), whereas the pneumococcus vaccine had the lowest (32-53%). Full scheme vaccine coverage decreased from 37.80% to 24.77% in 2012 and 2021, respectively. The National Health Card property, morbidity, being a beneficiary of any health system institution, and use of preventive services increased the probability of vaccine uptake. In conclusion, vaccine coverage in older Mexican adults decreased over time, and the Mexican health system plays a strategic role in immunisation.

Factors Associated with Annual Influenza Vaccination Uptake in U.S. Older Adults from 2019 to 2020

Annual influenza vaccination is important for older adults to prevent morbidity and mortality from seasonal influenza. Although the United States has had limited success in increasing influenza vaccination, the rise of the COVID-19 pandemic in 2020 may have changed older adults’ approach to vaccination. The objective of this study is to determine factors associated with influenza vaccination in 2019 and 2020 and compare their degree of associations across the two years. Data from the 2019 and 2020 National Health Interview Survey, a nationally representative cross-sectional interview, were collected for variables relating to annual influenza vaccination and possible associated factors. Data were analyzed using chi-square tests and multiple logistic regression. The results show that never having received a vaccination for pneumonia increased the odds of receiving an influenza vaccination by 6.79–7.80 times. Recent specialist care for eye or oral health significantly increased the odds of receiving an influenza vaccination. Being a smoker, identifying as African American, and considering oneself to have excellent overall health were associated with significantly lower odds of receiving a vaccination. Although self-reported feelings of anxiety were not associated with vaccination in 2019, they increased the odds in 2020. Overall, influenza vaccination in older adults may be tied to reliable healthcare access and perceived susceptibility to infectious respiratory diseases.

2139. Immunogenicity, reactogenicity and safety of a Respiratory Syncytial Virus prefusion F (RSVPreF3) candidate vaccine co-administered with the seasonal quadrivalent influenza vaccine in older adults

Abstract Background Respiratory syncytial virus (RSV) can cause severe respiratory disease in older adults (OAs). However, there is no approved vaccine against RSV disease in OAs. Co-administration of vaccines against RSV and influenza could be considered given their overlapping seasonality. Here, we assessed the immunogenicity, reactogenicity and safety of an RSV prefusion F Older Adult (RSVPreF3 OA) investigational vaccine when co-administered with the seasonal quadrivalent influenza vaccine (FLU-QIV) in OAs. Methods In this Phase 3, open-label, controlled, multi-country study (NCT04841577), OAs aged ≥ 60 years recruited in New Zealand, Panama and South Africa were randomized 1:1 to receive either RSVPreF3 OA and FLU-QIV simultaneously on day 1 (Co-Ad group), or FLU-QIV on day 1 and RSVPreF3 OA on day 31 (Control group). The co-primary objectives were to demonstrate the non-inferiority of i) RSVPreF3 OA in terms of RSV-A neutralizing antibody geometric mean titers (GMT) ratio and ii) FLU-QIV in terms of hemagglutinin inhibition antibody GMT ratio for each Flu strain when co-administered versus when administered alone. Blood samples were collected from all participants pre vaccination and 1 month post vaccination. Non-inferiority was demonstrated if the upper limit (UL) of the 95% confidence interval (CI) of the group GMT ratio (Control/Co-Ad) was ≤ 1.5. Secondary descriptive outcomes included reactogenicity and safety. Results 885 participants received at least 1 dose of the study interventions. Of these, 838 were included in the per protocol set at 1 month post vaccination. The demographic characteristics of the participants were similar across groups. The study co-primary objectives were met; for both vaccines, the UL of the 95% CI of the GMT ratio was ≤ 1.5 (Table 1). The observed safety events were balanced between Co-Ad and Control groups (Table 2). The reactogenicity profile of the Co-ad group compared with the Control group was driven by the RSVPreF3 OA investigational vaccine. Conclusion Our results support simultaneous seasonal vaccination with RSVPreF3 OA and FLU-QIV in adults ≥ 60 years, as co-administration elicits a statistically non-inferior immune response to the administration of each vaccine alone, with no safety concerns identified. Disclosures Nathali Montenegro, MD, GSK: Support for the present abstract/study Lorena Noriega-Aguirre, MD, ScD, Astra Zeneca: Advisor/Consultant|Astra Zeneca: Honoraria|Astra Zeneca: Support for attending meetings and/or travel|Boehringer Ingelheim: Honoraria|Boehringer Ingelheim: Support for attending meetings and/or travel|GSK: Advisor/Consultant|GSK: Support for the present abstract/study|Novartis: Honoraria Mohammed Bensellam, PhD, GlaxoSmithKline Biologicals SA: Agency worker on assignment at GSK Nathalie De Schrevel, PhD, GlaxoSmithKline Biologicals SA: Employee|GlaxoSmithKline Biologicals SA: Ownership Interest Sherine Kuriyakose, MSc, GSK: GSK Employee Axel Lambert, MSc, GSK: GSK Employee Aurélie Olivier, PhD, GlaxoSmithKline Biologicals SA: I’m an employee of GSK Biologicals|GlaxoSmithKline Biologicals SA: Ownership Interest Veronica Hulstrøm, PhD MD, GlaxoSmithKline Biologicals SA: Employee.

102. Efficacy and Effectiveness of High-Dose Influenza Vaccine in Older Adults by Age and Seasonal Characteristics: An Updated Systematic Review and Meta-Analysis

Abstract Background High-dose influenza vaccine (HD-IIV) has been used extensively in older adults since its approval in 2009. Studies comparing HD-IIV to standard-dose influenza vaccines (SD-IIV) have demonstrated protection beyond influenza, including reduction of outcomes like cardiorespiratory and all-cause hospitalizations. This study is an update of previously-conducted reviews of the relative vaccine efficacy/effectiveness (rVE) of HD-IIV vs. SD-IIV in adults ≥65 years against influenza-associated outcomes from 2009-2020, with sub-analyses by seasonal and recipient characteristics. Methods An updated systematic review and meta-analysis was conducted for studies assessing the rVE of HD-IIV against probable/laboratory-confirmed influenza-like illness (ILI), emergency department (ED) and/or hospital admissions in adults ≥65 years. Results from individual seasons – stratified by outcome, subject characteristics, and influenza season, were meta-analyzed to estimate pooled rVEs of HD-IIV. Results 19 studies from 11 consecutive seasons with over 45 million HD-IIV or SD-IIV recipients were meta-analyzed. Overall, HD-IIV demonstrated improved protection vs. SD-IIV against ILI (rVE=14.3%, 95%CI:4.2-23.3%), HD-IIV was more effective at preventing hospital/ED visits due to influenza (rVE=10.4%, 95%CI:6.8-13.9%), and hospitalizations due to influenza (rVE=11.2%, 95%CI:7.4-14.8%), pneumonia (rVE=27.3%, 95%CI:15.3-37.6%); pneumonia and influenza (rVE=13.4%, 95%CI:7.3-19.2%); respiratory (rVE=14.3%, 95%CI:8.5-20.0%), cardiovascular (rVE=13.1%, 95%CI:10.5-15.7%), and cardiorespiratory events (rVE=17.9%, 95%CI:15.0-20.8%); and all-causes (rVE=8.4%, 95%CI:5.7-11.0%). Pooled rVEs were similar in sub-analyses by dominant strain, antigenic match, and study type/setting. While all adults 65+ benefited from the use of HD-IIV, age-stratified analyses of the rVE of HD-IIV suggested additional relative benefit with increasing age. Conclusion Evidence over 11 consecutive influenza seasons from both randomized and observational studies suggests HD-IIV was consistently more effective than SD-IIV at reducing influenza and associated serious outcomes irrespective of recipient age and characteristics of the influenza season. Disclosures Jason K. Lee, MS, MBiotech, Sanofi: Employee|Sanofi: Stocks/Bonds Gary K. Lam, PharmD, RPh, Sanofi: Employee Rolan Vaisman, PharmD, RPh, Sanofi: Employee Kevin J. Yin, MD, MPH, PhD, Sanofi: Employee|Sanofi: Stocks/Bonds Bruce T. Seet, PhD, MBA, Sanofi: Employee|Sanofi: Stocks/Bonds Matthew M. Loiacono, PhD, MSc, Sanofi: Employee|Sanofi: Stocks/Bonds Sandrine I. Samson, PhD, Sanofi: Employee|Sanofi: Stocks/Bonds.

Leaving no one behind: Defining and implementing an integrated life course approach to vaccination across the next decade as part of the immunization Agenda 2030

Strategic Priority 4 (SP4) of the Immunization Agenda 2030 aims to ensure that all people benefit from recommended immunizations throughout the life-course, integrated with essential health services. Therefore, it is necessary for immunization programs to have coordination and collaboration across all health programs. Although there has been progress, immunization platforms in the second year of life and beyond need continued strengthening, including booster doses and catch-up vaccination, for all ages, and recommended vaccines for older age groups.We note gaps in current vaccination programs policies and achieved coverage, in the second year of life and beyond. In 2021, the second dose of measles-containing vaccine (MCV2), given in the second year of life, achieved 71% global coverage vs 81% for MCV1. For adolescents, 60% of all countries have adopted human papillomavirus vaccines in their vaccination schedule with a global coverage rate of only 12 percent in 2021. Approximately 65% of the countries recommend influenza vaccines for older adults, high-risk adults and pregnant women, and only 25% recommended pneumococcal vaccines for older adults.To achieve an integrated life course approach to vaccination, we reviewed the evidence, gaps, and strategies in four focus areas: generating evidence for disease burden and potential vaccine impact in older age groups; building awareness and shifting policy beyond early childhood; building integrated delivery approaches throughout the life course; and identifying missed opportunities for vaccination, implementing catch-up strategies, and monitoring vaccination throughout the life course. We identified needs, such as tailoring strategies to the local context, conducting research and advocacy to mobilize resources and build political will. Mustering sufficient financial support and demand for an integrated life course approach to vaccination, particularly in times of COVID-19, is both a challenge and an opportunity.

The impact of circadian rhythms on the immune response to influenza vaccination in middle-aged and older adults (IMPROVE): a randomised controlled trial

BackgroundVaccination is important in influenza prevention but the immune response wanes with age. The circadian nature of the immune system suggests that adjusting the time of vaccination may provide an opportunity to improve immunogenicity. Our previous cluster trial in Birmingham suggested differences between morning and afternoon vaccination for some strains in the influenza vaccine in older adults. Whether this effect is also seen in a younger age group with less likelihood of compromised immunity is unknown. We therefore conducted an individual-based randomized controlled trial in Guangzhou to test the hypothesis that influenza vaccination in the morning induces a stronger immune response in older adults than afternoon vaccination. We included adults in middle age to determine if the effect was also seen in younger age groups.ResultsOf the 418 participants randomised, 389 (93.1%, 191 middle-aged adults aged 50–60 years and 198 older adults aged 65–75 years) were followed up. Overall, there was no significant difference between the antibody titers (geometric mean /95% CI) after morning vs afternoon vaccination (A/H1N1: 39.9 (32.4, 49.1) vs. 33.0 (26.7, 40.7), p = 0.178; A/H3N2: 92.2 (82.8, 102.7) vs. 82.0 (73.8, 91.2), p = 0.091; B: 15.8 (13.9, 17.9) vs. 14.4 (12.8, 16.3), p = 0.092), respectively. However, in pre-specified subgroup analyses, post-vaccination titers for morning versus afternoon vaccination in the 65–75 years subgroup were (A/H1N1): 49.5 (36.7, 66.6) vs. 32.9 (24.7, 43.9), p = 0.050; (A/H3N2): 93.5 (80.6, 108.5) vs. 73.1 (62.9, 84.9), p = 0.021; (B): 16.6 (13.8, 20.1) vs. 14.4 (12.3, 17.0), p = 0.095, respectively. Among females, antibody titers for morning versus afternoon vaccination were (A/H1N1): 46.9 (35.6, 61.8) vs. 31.1 (23.8, 40.7), p = 0.030; (A/H3N2): 96.0 (83.5, 110.3) vs. 84.7 (74.4, 96.5), p = 0.176; (B): 14.8 (12.7, 17.3) vs. 13.0 (11.3, 14.9), p = 0.061, respectively. In the 50–60 years old subgroup and males, there were no significant differences between morning and afternoon vaccination.ConclusionsMorning vaccination may enhance the immunogenicity to influenza vaccine in adults aged over 65 and women. An intervention to modify vaccination programs to vaccinate older individuals in the morning is simple, cost free and feasible in most health systems.

Immunogenicity and safety of high-dose quadrivalent influenza vaccine in older adults in Taiwan: A phase III, randomized, multi-center study

BackgroundHigh-dose influenza vaccine offers better protection against influenza/associated complications compared with standard-dose formulation. We evaluated immunogenicity and safety of high-dose influenza vaccine (QIV-HD) and standard-dose (QIV-SD) in older adults (≥ 65 years) in Taiwan. MethodsThis was a phase III, randomized, modified double-blind, active-controlled, multi-center, descriptive study in older adults. Participants (N = 165) were randomized 1:1 to receive QIV-HD or QIV-SD vaccine (clinicaltrials.gov#NCT04537234). ResultsFor all four influenza strains, geometric means titers (GMTs) of hemagglutination inhibition were higher for the QIV-HD than QIV-SD with adjusted GMT ratios (95 % CI) of 2.65 (1.87–3.75) for A/H1N1; 1.76 (1.31–2.38) for A/H3N2; 2.60 (1.90–3.56) for B/Victoria; and 2.01 (1.57–2.56) for B/Yamagata. The seroconversion was higher for QIV-HD than QIV-SD with similar safety profiles across both groups. ConclusionQIV-HD was highly immunogenic for four influenza strains and have acceptable safety profile in older adults aged ≥ 65 years in Taiwan.

Adjuvanted versus non-adjuvanted standard-dose influenza vaccines in preventing all-cause hospitalizations in the elderly: a cohort study with nested case-control analyses over 18 influenza seasons

ABSTRACT Background The higher effectiveness of adjuvanted trivalent influenza vaccine (aTIV) versus non-adjuvanted (na) formulations in preventing all-cause hospitalization has been demonstrated for a single influenza season and in institutionalized elderly only. This study evaluated the relative vaccine effectiveness for aTIV vs. non-adjuvanted trivalent (naTIV) and/or quadrivalent (naQIV) influenza vaccines in preventing all-cause hospitalizations across 18 influenza seasons in primary care. Research design and methods Using Health Search Database, a nested case-control analysis was conducted in a cohort of older adults being vaccinated with aTIV or naTIV/naQIV. Conditional logistic regression was adopted to estimate the odds ratio (OR) of all-cause hospitalizations occurred during the epidemic period. Results Of 58,252 patients vaccinated with aTIV and naTIV/naQIV for the first time, 2,504 cases of all-cause hospitalization (3.46 per 1,000 person-weeks) during the 18 influenza seasons were identified. Compared with naTIV/naQIV, aTIV was associated with a 12% reduced the odds of all-cause hospitalizations (OR 0.88; 95% CI: 0.80–0.97). Conclusions In an 18-season cohort of older adults, aTIV reduced the risk of all-cause hospitalizations when compared with naTIV/naQIV. Our findings confirm additional benefits for adjuvanted influenza vaccines in older adults.

Life Satisfaction and Influenza Vaccination Among Older Adults in Canada.

Older adults have an increased risk of complications or death from influenza. Despite the benefits of vaccination for older adults, vaccination coverage among older adults ages 65 years and over is still below Canada's national target of 80 per cent. As health-care-seeking behaviours are influenced by several factors, including life satisfaction, we investigated the relationship between life satisfaction and influenza vaccination among older adults. A sample (n = 22,424) from the 2015-2016 Canadian Community Health Survey data was analysed using descriptive and multinomial logistic regression analyses. Higher life satisfaction was associated with a more recent influenza vaccination history. Vaccination differed by gender, age, and self-reported health status, as women, much older adults, and those with the poorest health status were more likely to be vaccinated. The study suggests an association between life satisfaction and influenza vaccination. More research into the factors that impact influenza vaccination in older adults is needed to increase vaccination coverage in the older adult population.

The Immunogenicity and Safety of Influenza Vaccines among Indonesian Older adult

BACKGROUND: Immunosenescence, frailty, sarcopenia, and Vitamin D deficiency were thought of having a negative influence on adequate immune response following vaccination. Epidemiological data related to influenza vaccination and its immunogenicity and safety in Indonesia are still scarce. AIM: This study aimed to assess the immunogenicity and safety of the influenza vaccine in older adults in Indonesia and common related conditions. METHODS: This study was a one-group, pre-test, post-test, quasi-experimental study. The vaccine used was a trivalent type. Immunogenicity was assessed according to rate of seropositivity and seroconversion based on hemagglutination inhibition antibody titer. Immunization safety was assessed according to adverse events following immunization (AEFI). RESULTS: A total of 227 subjects were involved in this study. Antibody titers were significantly increased after 28-day influenza vaccination for all strains (p < 0.001). Seropositive rate in 28-day post-vaccination for A/H1N1, A/H3N2, and influenza B was 98.7%, 99.1%, and 97.4%, respectively. Meanwhile, the seroconversion rate for A/H1N1, A/H3N2, and influenza B strains was 54.2%, 66.1%, and 60.4%, respectively. The conditions of the frailty status, sarcopenia, and Vitamin D level were not associated with either seroconversion or seropositive status, both at baseline and endpoint. AEFI was occurred on seven subjects (3.08%) with pain at the injection site and one subject (0.44%) with arm tenderness. CONCLUSION: Influenza vaccination showed adequate immune response and safety regardless of the frailty status, sarcopenia, or Vitamin D level. This result strengthened the importance of influenza vaccine administration in Indonesia older adults.

Economic Burden and Health-Related Quality of Life of Respiratory Syncytial Virus and Influenza Infection in European Community-Dwelling Older Adults.

Respiratory syncytial virus (RSV) and influenza virus infections result in a considerable mortality and morbidity among the aging population globally. Influenza vaccination for older adults before the seasonal influenza epidemic has been evaluated to be cost-effective in many countries. Interventions against RSV in older adults are in the pipeline, and evaluating their cost-effectiveness is crucial for decision making. To inform such evaluations, our aim was to estimate average costs and health-related quality of life (HRQoL) in older adults with RSV and influenza infection. The European RESCEU observational cohort study followed 1040 relatively healthy community-dwelling older adults aged 60 years and older during 2 consecutive winter seasons. Health care resource use and HRQoL were collected and analyzed during RSV episodes, and also during influenza episodes. Country-specific unit cost data were mainly obtained from national databases. Direct costs were estimated from a patient, health care provider, and health care payers' perspective, whereas indirect costs were estimated from a societal perspective. Due to small sample size, no formal statistical comparisons were made. Thirty-six RSV and 60 influenza episodes were reported, including 1 hospitalization. Means (median; first-third quartile) of €26.4 (€5.5; 0-47.3) direct and €4.4 (€0; 0-0) indirect costs were reported per nonhospitalized RSV episode, and €42.5 (€36; 3.3-66.7) direct and €32.1 (€0; 0-0) indirect costs per nonhospitalized influenza episode. For RSV episodes, the utility value decreased from 0.896 (0.928; 0.854-0.953) to 0.801 (0.854; 0.712-0.937) from preseason to 1 week after symptom onset; for influenza, the change was from 0.872 (0.895; 0.828-0.953) to 0.664 (0.686; 0.574-0.797). The average costs and HRQoL estimates of older adults treated outside the hospital can be used to inform the design of future studies and the decision making regarding interventions to prevent RSV infection in older adults. Larger studies are needed to provide better country-specific and complementary cost estimates and to allow for formal statistical comparison of costs between RSV and influenza. NCT03621930.

Effectiveness of influenza vaccination in the elderly: a population-based case-crossover study

BackgroundThere is limited information regarding the effectiveness of influenza vaccines for older adults. Particularly, controlling for healthy senior bias is challenging in observational studies. We aimed to assess the efficacy...

Impact of diabetes status on immunogenicity of trivalent inactivated influenza vaccine in older adults.

Individuals with type 2 diabetes mellitus experience high rates of influenza virus infection and complications. We compared the magnitude and duration of serologic response to trivalent influenza vaccine in adults aged 50–80 with and without type 2 diabetes mellitus. Serologic response to influenza vaccination was similar in both groups: greater fold‐increases in antibody titer occurred among participants with lower pre‐vaccination antibody titers. Waning of antibody titers was not influenced by diabetes status.

Sex-specific effects of aging on humoral immune responses to repeated influenza vaccination in older adults

Older adults (≥65 years of age) bear a significant burden of severe disease and mortality associated with influenza, despite relatively high annual vaccination coverage and substantial pre-existing immunity to influenza. To test the hypothesis that host factors, including age and sex, play a role in determining the effect of repeated vaccination and levels of pre-existing humoral immunity to influenza, we evaluated pre- and post-vaccination strain-specific hemagglutination inhibition (HAI) titers in adults over 75 years of age who received a high-dose influenza vaccine in at least four out of six influenza seasons. Pre-vaccination titers, rather than host factors and repeated vaccination were significantly associated with post-vaccination HAI titer outcomes, and displayed an age-by-sex interaction. Pre-vaccination titers to H1N1 remained constant with age. Titers to H3N2 and influenza B viruses decreased substantially with age in males, whereas titers in females remained constant with age. Our findings highlight the importance of pre-existing immunity in this highly vaccinated older adult population and suggest that older males are particularly vulnerable to reduced pre-existing humoral immunity to influenza.

Comparison of the safety and immunogenicity of a novel Matrix-M-adjuvanted nanoparticle influenza vaccine with a quadrivalent seasonal influenza vaccine in older adults: a phase 3 randomised controlled trial

Improved seasonal influenza vaccines for older adults that can induce broadly cross-reactive antibodies and enhanced T-cell responses, particularly against A H3N2 viruses, while avoiding egg-adaptive antigenic changes, are needed. We aimed to show that the Matrix-M-adjuvanted quadrivalent nanoparticle influenza vaccine (qNIV) was immunologically non-inferior to a licensed, standard-dose quadrivalent inactivated influenza vaccine (IIV4) in older adults. This was a phase 3 randomised, observer-blinded, active-comparator controlled trial done across 19 US community-based clinical research sites during the 2019-20 influenza season. Participants were clinically stable and community-dwelling, aged at least 65 years, and were randomised in a 1:1 ratio using an interactive web response system to receive a single intramuscular dose of qNIV or IIV4. The primary objective was to describe safety and show that qNIV was immunologically non-inferior to IIV4. The primary outcomes were adverse events by treatment group and comparative haemagglutination-inhibiting antibody responses (assayed with egg-propagated virus) on day 28, summarised in terms of the ratio of geometric mean titres (GMTRqNIV/IIV4) and seroconversion rate (SCR) difference between participants receiving qNIV or IIV4 for all four vaccine homologous influenza strains. The immunogenicity outcome was measured in the per-protocol population. Non-inferiority was shown if the lower bound of the two-sided 95% CI on the GMTRqNIV/IIV4 was at least 0·67 and the lower bound of the two-sided 95% CI on the SCR difference -was at least -10%. The study is registered with clinicaltrials.gov, NCT04120194, and is active and not recruiting. 2742 adults were assessed for eligibility and 2654 were enrolled and randomised between Oct 14, 2019, and Oct 25, 2019; 1333 participants were randomised to the qNIV group and 1319 to the IIV4 group (two participants withdrew consent before being assigned to a group). qNIV showed immunological non-inferiority to IIV4: GMTRqNIV/IIV4 for the four vaccine homologous influenza strains was A/Brisbane 1·09 (95% CI 1·03 to 1·15), A/Kansas 1·19 (1·11 to 1·27), B/Maryland 1·03 (0·99 to 1·07), and B/Phuket 1·23 (1·16 to 1·29); and SCR difference was A/Brisbane 5·0 (95% CI 1·9 to 8·1), A/Kansas 7·3 (3·6 to 11·1), B/Maryland 0·5 (-1·9 to 2·9), and B/Phuket 8·5 (5·0 to 11·9). 659 (49·4%) of 1333 of participants in the qNIV group and 551 (41·8%) of 1319 participants in the IIV4 group had at least one treatment-emergent adverse event. More solicited adverse events were reported by participants in the qNIV group (551 [41·3%] of 1333) than in the IIV4 group (420 [31·8%] of 1319), and were comprised primarily of mild to moderate transient injection site pain (341 [25·6%] in the qNIV group vs 212 [16·1%] in the IIV4 group). qNIV was well tolerated and produced qualitatively and quantitatively enhanced humoral and cellular immune response in older adults compared with IIV4. qNIV might enhance the effectiveness of seasonal influenza vaccination, and future studies to show clinical efficacy are planned. Novavax.