PROGRESS AND PROBLEMS OF VACCINATION AGAINST CORONAVIRUS INFECTION COVID-19

Abstract

. The pandemic of coronavirus infection caused by COVID-19 is an urgent problem today. Therefore, the search for optimal and safe ways to prevent the occurrence of this infection or its severe consequences is of great interest to scientists and clinicians worldwide. The most effective way to do this is vaccination, which, unfortunately, in the case of COVID-19, is only effective when the antigenic structure of the circulating virus matches the antigens contained in the vaccine. However, the emergence of new strains, due to the ability of the coronavirus to constantly change, which differ from circulating variants and have pandemic potential, leads to the ineffectiveness of previously proposed vaccines. Therefore, this work aimed to determine the main approaches to creating vaccines and the advantages and disadvantages of vaccination by conducting a bibliographic analysis of modern scientific publications. The main approaches to creating a vaccine against COVID-19 were characterized, in particular: vaccines based on an attenuated virus, inactivated vaccines, vector vaccines, protein vaccines, and vaccines based on nucleic acids. The main advantages and disadvantages of each of the proposed options are described. Considerable attention is paid to the issue of immunological imprinting and antibody-dependent enhancement of infection. A detailed analysis of these phenomena was carried out, and their influence on the effectiveness of various vaccines was described. It was established that the use of DNA and RNA vaccines, provided that the problem of their low immunogenicity in humans is solved, is a real alternative for the future development of medicine in the prevention of infectious diseases. The importance of considering the possibility of complications associated with the phenomena of antigenic imprinting and antibody-dependent enhancement of infection when developing vaccines and carrying out mass vaccinations has been proven. Since the complications underlying these phenomena can appear decades after the previous vaccination or epidemic. In addition, the vaccination itself, carried out without taking them into account, can complicate the epidemic process or cause the development of an epidemic of a closely related virus in those areas where this virus and the one against which the vaccination was carried out circulate at the same time.

Keywords

• vaccination,coronavirus infection,covid-19,vaccine,immunological imprinting,antibodydependent enhancement of infection.