Determinants of the Seasonal Influenza Vaccination Uptake Among People Aged 50 Years or Above During and After the Pandemic: A Systematic Review

Abstract

Background/Objectives: Seasonal influenza vaccination (SIV) coverage remains suboptimal among adults aged ≥50 years, and the COVID-19 pandemic might influence the determinants of SIV uptake. This systematic review aimed to identify determinants of SIV uptake among adults aged ≥50 years during and after the COVID-19 pandemic. Methods: We searched PubMed, MEDLINE, Embase, Web of Science, Global Health, CINAHL, Cochrane Library, APA PsycINFO, and APA PsycArticles for studies published between 1 December 2019 and 1 January 2026. The pooled prevalence of SIV uptake was synthesized using random-effects models in meta-analysis. Results: A total of 50 studies were included in the systematic review. COVID-19-related factors, such as perceived risk of co-infection with SARS-CoV-2 and seasonal influenza and concerns about potential interactions between COVID-19 vaccines and SIV, were determinants of SIV uptake. Other modifiable determinants included those that existed before the pandemic (e.g., knowledge and perceptions of seasonal influenza and SIV). Subgroup analysis showed that cost and inaccessibility were barriers to receiving SIV in places without a fully subsidized SIV, and perceived susceptibility and vaccine safety concerns were commonly identified as facilitators and barriers in studies with data collected after the pandemic. The pooled prevalence of SIV uptake among adults aged 50 years or above was 53% (95% confidence interval: 44–62%). Such uptake appeared lower among adults aged 50–64 years, in regions without a fully subsidized SIV, and after the COVID-19 pandemic. Conclusions: These findings could inform service planning and interventions promoting SIV uptake among adults aged ≥50 years in the post-pandemic era. More studies are needed to explore determinants specific to people aged 50–64 years to inform health promotion tailored to their needs.