The study is a prospective cohort study. Weekly (in the first phase) and bi-weekly (in the second phase) serum samples will be drawn and shipped bi-weekly to laboratory collaborators in United Kingdom for antibody analyses during the course of the local epidemic, expected to last 10-12 weeks or more. After the cease of the epidemic serum will be drawn in 3-monthly intervals in a smaller group of seroconverted volunteers to follow the long-lasting immunity of SARS-CoV-2 infection up to 5 years post-pandemic.

Nurses, medical doctors, biomedical laboratory scientists, social health care assistants, and few healthcare administrators (as controls) will be invited for enrolment. In hospitals, all departments with staff that are in physical contact with patients during the pandemic will be invited to participate in the study.