Individual Factors Influencing the Public's Perceptions About the Importance of COVID-19 Immunity Certificates in the United Kingdom: Cross-sectional Web-based Questionnaire Survey.

Background: Understanding how perceptions around immunity certificates are influenced by individual characteristics is important to inform evidence-based policy making and implementation strategies for services around immunity and vaccine certification.

Objective: This study aimed to assess what were the main individual factors influencing people's perception of the importance of using COVID-19 immunity certificates, including health beliefs about COVID-19, vaccination views, sociodemographics, and lifestyle factors.

Methods: A cross-sectional web-based survey with a nationally representative sample in the United Kingdom was conducted on August 3, 2021.