Hacettepe University COVID-19 Vaccinated's Health Cohort- Students of Health Sciences

The first COVID-19 case in Turkey was reported on March 11, 2000. National COVID-19 mass vaccination was initiated on Jan 13, 202, with two doses of CoronaVac (R) inactivated vaccine (of Sinovac), 28 days apart. The health personnel were prioritized in the mass vaccination, given their high rates of exposure and fatality. National COVID-19 statistics have been limited to those announced in the media; data breakdown by gender, age, vaccine type and status etc. is not provided, nor is the association between non-pharmaceutical preventive measures (NPPM) and infection rates. Well-planned, longitudinal, detailed studies with laboratory support are clearly warranted. Hacettepe University is a leading institution in Turkey, with its large health sciences campus. Students of medical school (grades 4, 5, and 6) and dental school (grades 4 and 5) have been actively providing patient care in HU Hospitals, and more than 10% of medical interns had been reportedly diagnosed as COVID-19 cases prior to vaccination activities, despite (reportedly) strict non-pharmaceutical public preventive measures (NPPM) use inside/outside the occupational settings. A two-year prospective cohort study was planned for periodic evaluation of students' general health status and COVID-19 risk/exposure/infection, for timely referrals and quarantine/isolation, as needed. Anti- SARS-CoV-2-RBS antibodies will be measured periodically after vaccination, together with evaluation of potential adverse effects, presence and durability of vaccine-induced immunity. Comparison of antibody levels were planned for incident COVID-19 cases and two test-negative controls of the same gender, attending the same grade and faculty. A subcohort will be followed for aymptomatic infection risk. Institutional ethical approvals were obtained, as required. A step-wise informed consent was obtained from all participants, all tests will be done with de-personalized records, and all statistical analyses and reporting will be comp