Assessment of humoral immunity to SARS-CoV-2 among employees of medical organizations in the Republic of Tatarstan

BACKGROUND: Since the beginning of the new coronavirus infection pandemic, preventive measures aimed at combating the spread of the pathogen and preventing the development of severe forms of infection and deaths have improved. Despite the absence of a legally established, generally accepted post-vaccination protective value of antibodies to coronavirus, the study of the presence of antibodies and the determination of their amount in the blood serum of the vaccinated population continues.

AIM: This study presents the results of post-vaccination humoral immunity to SARS-CoV-2 in medical organizations regardless of their infectious disease history.

MATERIALS AND METHODS: This study involved employees of medical organizations of the State Autonomous Health Institution “Republican Clinical Dermatovenerologic Dispensary of the Ministry of Health of the Republic of Tatarstan named after Professor A.G. Ge” in Kazan and the State Autonomous Health Institution “City Polyclinic No. 3” in Naberezhnye Chelny. Three hundred ninety-three people (including 350 women) were vaccinated with the two-component vaccine GamCovidVac (Sputnik V). After a sufficient amount of time passed for the formation of an immune response, more than 21 days. The blood sera of these 393 people were examined for the determination of specific IgG to SARS-CoV-2 by enzyme immunoassay using the Vector-Best kit (Novosibirsk, Russia). Statistical analysis was performed using StatTech v.3.0.9 (developer, Stattech LLC, Russia).

RESULTS: The median age of the subjects was 47 (Q₁–Q₃: 39–59) years. The mean antibody titer level was 570 (Q₁–Q₃: 128–1150 BAU/ml). A correlation analysis of the relationship between titer levels and age at the time of vaccination was performed. According to the results, a weak direct relationship was established. There was no connection when assessing the antibody titer level dependence on vaccination duration after the second component at the time of checking the titers.

CONCLUSIONS: The ongoing pandemic of a new coronavirus infection with the emergence of new forms of the disease caused by other virus strains, the improvement in prevention methods, requires constant monitoring of the epidemiological situation with the study of the vaccine effectiveness, including the cellular level.