Comparative Cohort Epidemiological Study of Collective Immunity against New Coronavirus Infection among Different Groups of Military Personnel

Abstract

Background. The need to study the population immunity to the SARS-CoV-2 virus is due to the intensive spread of COVID-19 and the implementation of immunoprophylaxis of this infection. The identification of the features of the formation of immunoresistance in organized military collectives will allow us to predict the development of the epidemic situation, including among comparable population groups.
 Aims the study of population immunity to the SARS-CoV-2 virus in the context of the COVID-19 pandemic against the background of specific immunoprophylaxis in organized military collectives.
 Methods. According to epidemiological indications, an epidemiological study of collective immunity to the SARS-CoV-2 virus was conducted against the background of vaccination among cadets of military educational organizations. The study involved 497 people, divided into groups by epidemiological and vaccination history for COVID-19, blood groups and Rh factor. The assessment of the immunity intensity was carried out by the levels of class G immunoglobulins (IgG) to SARS-CoV-2 in the blood serum by the method of solid-phase enzyme immunoassay.
 Results. Seroprevalence in the total sample was 92.6%. The highest rates were observed among vaccinated patients: those who were not ill and vaccinated 99.0 0.7%, those who were ill and vaccinated-100% (mean geometric antibody titers 1:2234 and 1:4399). Among the ill, unvaccinated individuals, the seroprevalence index was 84.5 3.2% (1:220). Among those who were not ill, not vaccinated 8.2 3.1% (1:113), which may indicate a hidden course of the epidemic process in the team. A negative immune response was more common (tSt = 2.01; p 0.05) in individuals A(II)Rh+ blood group. The highest proportion of maximum antibody titers (1:32001:6400) was determined in AB(IV) individuals. Rh-blood groups (tSt=2.21; p 0.05).
 Conclusions. For the first time, the formation of combined immunity with the highest concentrations of specific antibodies was revealed in patients who have been ill and vaccinated has been revealed, which allows us to recommend vaccination to those who have suffered from COVID-19. The emergence of post-infectious immunity in organized groups with a latent epidemic process has been established. The relationship between the intensity of immunity with blood groups and the Rh factor was found.