Immunochemical diagnostic methods are widely used in the diagnosis of infectious diseases. Since beginning COVID-19 pandemic most manufacturers of diagnostic test systems also began to produce diagnostic kits for various markers of the virus with using immunochemical methods (enzyme immunoassay, immunochromatography, chemiluminescence).

Objective. To assess the diagnostic value of the available test systems for the detection of antibodies to various antigens and in various formats to the SARS-CoV-2 virus

Materials and methods. The study was conducted on the basis of the Minsk clinical infectious disease hospital, the test material was the blood sera of patients with COVID-19 and hospital staff (N-1511).

Results. When testing blood sera for antibodies to various antigenic determinants of the virus SARS-CoV-2 (S and
N-Ag) a greater number of positive samples for antibodies to S-Ag were found. Quantification of antibodies to S-Ag of the SARS-CoV-2 virus showed that the content of antibodies in an amount of more than 1000 Bau/мл in 82 % of cases was observed in persons with combined immunity

(post-vaccination and post-infection).

Conclusion. Screening studies for diagnostic and epidemiological purposes for coronavirus infection are optimally performed using test systems for total antibodies. In the absence of these test systems, limit yourself to IgG to S-AG virus SARS-CoV-2. To assess the intensity of post-vaccination or post-infection immunity to the causative agent of COVID-19 to use a quantitative test taking into account the epidemiological anamnesis.