Acceptance of the Influenza Vaccine and Its Impact on Hospitalization and Mortality: A Systematic Review (2019–2025)

Abstract

Background: Influenza remains a significant cause of preventable morbidity and mortality in Latin America. Vaccination is the most effective strategy to reduce severe complications, hospitalizations, and deaths; however, vaccine acceptance varies considerably across countries and population groups. Objective: To analyze the association between influenza vaccine acceptance and health outcomes reported in Latin America during the period 2019–2025. Methods: A systematic review with narrative synthesis was conducted following the PRISMA 2020 guidelines. A comprehensive literature search was performed in PubMed, SciELO, and Dialnet. Original studies published between 2019 and 2025 that assessed factors associated with influenza vaccine acceptance and its relationship with morbidity and mortality indicators were included. Study selection and analysis were carried out according to predefined criteria. Results: Five studies conducted in Brazil, Chile, and Uruguay met the inclusion criteria. Trust in vaccines, healthcare professional recommendation, and perceived risk of disease were positively associated with vaccine acceptance. In contrast, misinformation, access barriers, and low perceived susceptibility were identified as the main determinants of vaccine hesitancy or refusal. Higher levels of vaccine acceptance were associated with reduced influenza-related hospitalizations and mortality. Conclusions: Influenza vaccine acceptance is positively associated with improved health outcomes in Latin America. Strengthening evidence-based communication strategies, promoting institutional trust, and ensuring equitable access to vaccination are essential to enhance the public health impact of immunization programs in the region.