Study on COVID-19 Immune Protection and Risk of Reinfection in Medical and Support Staff Over 48 Weeks

What this Trial Is About

This research aims to evaluate the protective effect of the immune barrier on secondary infection after COVID-19 vaccination or infection with the Omicron B A.5.2 strain. It focuses mainly on healthy participants, including medical staff, to understand how COVID-19 antibodies protect against different Omicron variants and to explore the best timing for COVID-19 vaccination after Omicron infection. The study is a single-center, prospective, non-intervention observational study involving about 300 participants such as medical, nursing, administrative, and logistics staff who can commit to 48 weeks of follow-up. Participants are divided into two groups based on their baseline COVID-19 antibody levels positive or negative. They will undergo regular COVID-19 antibody and nucleic acid tests every 4 to 8 weeks, with about seven visits planned over 48 weeks. If a participant tests positive for COVID-19 during the study, virus strain gene sequencing will be performed, and their participation will end early. During the study, participants will report any COVID-19 related symptoms and undergo antigen or nucleic acid testing within 48 hours if symptoms appear. The research team will monitor antibody titers, cellular immune function, and the incidence of secondary COVID-19 infections. This includes tracking changes in antibody levels and immune function over 48 weeks in both infected and uninfected individuals. The primary measure is the rate of COVID-19 reinfection between antibody positive and negative groups.

Evaluation of COVID-19 Immune Barrier and Reinfection Risk