ASSESSMENT OF POPULATION IMMUNITY TO THE SARS-COV-2 VIRUS AMONG THE POPULATION OF GRODNO

In Grodno, as well as in the Republic of Belarus as a whole, vaccination of the population against COVID-19 infection is being actively carried out. Purpose of the study: To assess population immunity to the SARS-CoV-2 virus among the population of the city of Grodno. The material of the study was the blood sera of 422 patients, residents of Grodno. Results. Among the studied subjects 32.7% (n=138) of cases had the level of class G antibodies to the receptor-binding domain (RBD) of the S protein (hereinafter RBD of the S protein) which was higher than 1.1 units of the positivity coefficient. A high seropositivity index (40.4%) was established among people who had not previously been infected with COVID-19 and were vaccinated with Sputnik V, the lowest – in the group of people who had not been infected with the infection and were not vaccinated – 25%. The assessment of the antibodies concentration adjusted for the age of the subjects did not reveal significant changes in their level. As regards the time interval, it was found that those individuals, who were vaccinated with Sputnik V vaccine regardless of whether they had been ill or not with COVID-19 infection before, had the highest level of antibodies within the second month after the last dose of the vaccine, which decreased by the fourth month after vaccination and remained at this level for up to six months.