Study Design
This is a multisite prospective longitudinal cohort study which enrolled at least 100,000 vaccinated and unvaccinated adults as its main Vaccine Effectiveness cohort, 24,000 individuals vaccinated with any one of the EUA-approved COVID-19 vaccines as its Subset 1 Vaccinated group and and at least 240 vaccinated and unvaccinated persons for frequent testing. Study participants were enrolled between July 1, 2021 and September 30, 2021 with follow-up of up to December 31, 2022.
Study Population
The study population were communities, workplaces, agencies or institutions in the Philippines where the Philippine National Deployment and Vaccination Plan for COVID-19 was implemented in September 2021.