Immunological Potency, Efficacy, and Tolerance of “Gam-COVID-Vac” Vaccine among Students: Prospective Study

Abstract

Background. Students, as the most active and mobile part of population, often unite into educational and informal groups, move to other regions or countries, and present a specific risk group for the spread of new coronavirus infection. Thus, they require preventive vaccination.Objective. The aim of the study is to study the immunological potency, tolerance, and efficacy of Gam-COVID-Vac vaccine among students of Krasnodar.Methods. 119 seronegative students (18-30 years old) were examined. SARS-CoV-2 IgG (ELISA method) was determined 1, 3, and 6 months after two completed rounds of vaccination. Post-vaccination adverse events and COVID-19 cases were evaluated in the study.Results. SARS-CoV-2 IgG level 1 month after vaccination ranged from 6.15 to 19.38 and was to 16.39 (AU/mL) ±1,12. Immunological potency values ranged from 4.407 to 21.5 (AU/mL) (14.74 ± 2.93) 3 months after. IgG titers were in the range of 4.14 to 17.71 (AU/mL) (10.97 ± 4.69) 6 months after. Adverse events after vaccination were revealed in 34 respondents (28.6%). Among them, local (hyperemia, pain, edema) — 21 (17.6%): slight — 90.4%, major — 9.6%; general (fever, weakness, algor, headache, arthralgia, myalgia) — 13 (10.9%): slight — 69.2%, major — 30.8%. The increase in vaccination coverage in students from 30.3 to 79.1% reduced the COVID-19 morbidity from 3.81 to 1.57%.Conclusion. Gam-COVID-Vac vaccine induced stable humoral response, demonstrated sufficient safety, and reduced morbidity 2.4-fold.