This study aimed to explore the relationship between post-vaccination adverse reactions, decision regret, and willingness to pay (WTP) for the booster dose. An online survey was conducted in Taizhou, China. Questionnaires were completed by 1,085 healthcare workers (HCWs) and 1,054 (97.1%) have received two doses of the COVID-19 vaccine. Mediation analysis method was adopted. Our study presented that post-vaccination adverse reactions in HCWs could decrease their WTP for the booster dose. Of note, HCWs experienced adverse reactions after vaccination would more likely regret their previous vaccination decisions, which, in turn, further reduced their WTP for a booster shot. Decision regret mediated the relationship between adverse post-vaccination reactions and WTP for the booster dose. The findings implied inextricable relationships among post-vaccination adverse reactions, decision regret, and WTP of the booster dose. It suggested that these post-vaccination adverse reactions should be further incorporated into vaccine campaigns to improve vaccine intention and potentially increase willingness to pay for booster doses of COVID-19 vaccine.
Keywords: COVID-19 booster vaccine; Healthcare workers; decision regret; vaccination adverse reaction; willingness-to-pay.