Abstract
Background: The vaccination against COVID-19 has already gone through advances in the world, yet vaccine hesitancy remains a challenge to reach maximum coverage and minimize further epidemics. New behavioral, informational, and structural problems define the new reality of the post-pandemic world. The key elements that contribute to the reluctance and the effectiveness of interventions need to be comprehended to accelerate additional vaccination.
Objectives: The aim of the proposed study is to perform a systematic review and evidence synthesis of (1) determinants of vaccine hesitancy in the post-COVID-19 era and (2) the impact of interventions that can be used to increase vaccine acceptance and uptake.
Methods: The systematic review was carried out based on PRISMA 2020 rules. Electronic searches (PubMed, Scopus, Web of Science and Google Scholar) were conducted and restricted studies were located based on limits of publication date (January 2019 to May 2025). The criteria used to include eligible studies were that the research conducted was on adults (18 years and above), that the study reported one of the predictors of hesitancy or one of the measures to raise uptake and had quantitative or qualitative results. Important determinants were extravasated, which included type of intervention and effect sizes (odds ratios [OR], risk ratios [RR], hazard ratios [HR]). The tools adopted in quality assessment were Cochrane Risk of Bias 2 tool in RCTs and Newcastle-Ottawa Scale in observational research.
Results: A total of 28 studies (n = 43,210 participants) were selected out of 2,346 reviewed. Fear of negative outcomes (78%), false information (61%), distrust in the health authorities (65%): These were the most prevalent reasons that contributed to hesitancy. The age, lack of education and residence in rural areas were significantly related with refusal (p < 0.01). Interventions: Owning customized health messages contributed significantly to the acceptance ( pooled OR = 1.26; 95% CI: 1.12 -1.42). The highest uptake improvements were created by pop-up clinic and community outreach (RR = 1.54; 95% CI: 1.30179) and the smallest, yet significant impact on the uptake was found with digital nudges (RR = 1.19; 95% CI: 1.05135). System trust: The more effective uptake was strongly correlated with greater trust (r = 0.68). Long-term outcomes of campaigns in high-trust contexts were greater as compared to low-trust contexts.
Conclusions: The primary determinants of vaccine hesitancy in the post COVID-19 period are the safety concerns, misinformation, and institutional distrust. The most effective ways to increase the uptake and mobilizations should be community-based, and the digital interventions must be offered equally and with support. Trust in the health systems should be developed so that sustainable vaccine acceptance is achieved. Future studies will aim at standardized outcome reportage and reconcile long term confidence and lead to convergence of behavioral and equity framework to influence resilient immunization