Monitoring the COVID-19 Vaccine Acceptance Trend and its Determinants Among Iranian Adults

Background: Vaccination seems to be the most critical means of halting the COVID-19 pandemic. It is crucial to understand the factors that influence COVID-19 vaccine acceptance to avoid low vaccination rates. This study intended to monitor the COVID-19 vaccine acceptance and its association with socio-demographic factors and prior diagnosis of COVID-19 in Iranian adults during the COVID-19 pandemic.Methods: The study utilized data from the COVID-19 Population Survey of Iran (COPSIR), a repeated national survey designed to monitor COVID-19-related behavioral insights. From April 2020 to November 2021, thirteen iterations of a series of cross-sectional studies involving computer-assisted telephone interviews were conducted. Results: The COVID-19 vaccine acceptance rate remained above 80% until the ninth wave in February 2021, when it dropped to 62.9%. However, throughout the next four surveys, it rose gradually from 72.0% to 85.7%. The multilevel regression model revealed that the COVID-19 vaccine acceptance was significantly and positively linked with age and education. Conclusion: Despite the relatively high COVID-19 vaccine acceptance rate among Iranian adults, after the emergence of vaccines on the global market and controversies about their safety in Iran, the initially high vaccine acceptance rate dropped significantly, and then increased over time and returned to its peak level (85%). According to the Commodity Theory, this rise in vaccine acceptance can be attributed to the COVID-19 vaccine shortage in the country between January and July 2022. For Iranian adults to accept vaccines more readily, health promotion programs should target the youth and the less literate adults.