Spillover between influenza and COVID-19 vaccination behaviors across pandemic phases and implications for general vaccine hesitancy

Achieving high vaccination coverage is a critical challenge during both crisis and routine outbreaks of infectious diseases. Previous studies have largely focused on single vaccination behaviors and vaccine-specific attitudes. A three-wave prospective longitudinal study was conducted to investigate the complex relationships between influenza vaccination behavior, COVID-19 vaccination behavior, and general vaccine hesitancy across different peri-pandemic phases. Uptake of pre-pandemic influenza vaccination was associated with uptake of full COVID-19 vaccination during the outbreak of COVID-19, which was further associated with uptake of influenza vaccination in the post-emergency phase when a strong resurgence of seasonal influenza occurred. The specific vaccination behaviors and negative general attitudes toward vaccination had reciprocal relationships across the peri-pandemic phases. Reduced negative attitudes toward vaccination mediated the spillover between influenza and COVID-19 vaccination behaviors. This suggests that general vaccine hesitancy could have a profound impact on shaping specific vaccination behaviors across target diseases and risk communication contexts. Two-tier promotion strategies can help effectively promote vaccinations and better prepare for future pandemics. © The Author(s) 2026.