Three-month results of vaccination of mono-stationary health workers with the drug «Gam-COVID-Vac»

ABSTRACT

Introduction. Antibodies are considered as a key immune effectors that provide protection against pathogenic threats. At the same time, the nature and duration of the antibody response to SARS-CoV-2 infection has not been precisely determined. The aim of the study was to determine the changes in the level of antibodies to SARSCoV-2 during immunization with the «Gam-COVID-Vac» vaccine. Material and methods. Observations were carried out with participance of 30 employees of the city clinical hospital No. 1. Medical workers were vaccinated against COVID-19 with the «Gam-COVID-Vac» vaccine according to the standard scheme. The level of antibodies was assessed on the 17th day after the administration of the 1st component of the vaccine, on the 17th and 30th days after the administration of the 2nd component of the vaccine. Results. Our studies show that the blood level of IgM antibodies to SARS-CoV-2 practically did not change on the 17th and 38th days after immunization with the 1st component (the average СP values were 1.616 and 1.75, respectively). However, by the 30th day, a decrease of IgM to SARS-CoV-2 was observed (average СP value - 0.7829). It should be noted that on the 17th day after immunization a significant variation was revealed in its indicators, which leveled off by the 30th day. A completely different picture was observed with the level of IgG antibodies to SARS-CoV-2. It significantly increased after immunization with the 2nd component and did not change until the 30th day (the average CP values were 12.36 and 12.48 on the 38th and 51st days, respectively). It is necessary to pay attention to the fact that after immunization with the 1st component on the 17th day, a low level of IgG to SARS-CoV-2 (CP - < 1) was recorded in 48 %, and after immunization with the 2nd component - only in 10 % vaccinated. At the same time by 51 days from vaccination the seroconversion level was 100 %. It should be noted that in some patients the IgG level changed by the 30th day after immunization, compared to the 17th day. Conclusion. Thus, our information confirms that the «Gam-COVID-Vac» vaccine is effective and, in more than 90 % of cases, leads to the formation of a sufficiently high level of antibodies against SARS-CoV-2.