Study on COVID-19 Vaccine Effectiveness Among Health Workers in Azerbaijan

Many critical questions remain about the effectiveness of COVID-19 vaccines in real-world settings. These questions can only be answered in post-introduction vaccine effectiveness studies. This protocol describes a prospective one-year cohort study of hospital-based HWs in Baku city of Azerbaijan to evaluate the effectiveness of COVID-19 vaccine in preventing laboratory-confirmed SARS-CoV-2 infection and COVID-19 disease. HWs are the target population in this study because HWs have been prioritized to be the first group to receive the vaccine in Azerbaijan and offer an early opportunity to evaluate the vaccine in a population in which it is critical that an effective vaccine be deployed. HWs will be enrolled 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. The target enrolment is 1500 HWs in six hospitals in Baku, the capital of Azerbaijan. At enrolment, study participants will complete a baseline enrolment e-survey about demographics, clinical comorbidities, and work- and community-related behaviours related to infection risk. In addition, a baseline serology will be collected from participants at enrolment. No PCR testing for COVID19 virus will be done at the time of enrollment. During the course of the study, participants will be actively followed for suspected symptomatic COVID-19 illness. Participants who meet a suspected case definition will be asked to have respiratory sample for SARS-CoV-2 by RT-PCR to be collected by trained HWs. PCR-positive samples from participants may also undergo genetic sequencing in or outside of Azerbaijan to identify the genetic makeup of the SARS-CoV-2 that caused the infection. Finally, at 6 months and 12 months of the study, serology will be collected from participants to confirm and quantify the