Many critical questions remain about the effectiveness of COVID-19 vaccines in real-world settings. It is important to carry out post-introduction vaccine effectiveness studies in selected countries to address these questions.
This guidance document outlines the methods of a prospective six-month cohort study of hospital-based healthcare workers (HWs) to evaluate the effectiveness of COVID-19 vaccine in preventing laboratory-confirmed SARS-CoV-2 infection (against any infection or against symptomatic infection only). HWs should be enrolled ideally prior to or simultaneous with the implementation of the COVID-19 vaccination campaign, after the study protocol is approved by the local ethical review committee. All HWs eligible to be vaccinated with COVID-19 vaccine can be enrolled in the study, including those who intend to get vaccinated, those who don’t plan on getting vaccinated, and those who are not sure whether or not they will be vaccinated.