ABSTRACT
Introduction. Despite widespread vaccination against COVID-19 worldwide, the epidemiological situation remains insufficient. The appearance of mutant forms of SARS-CoV-2 with increased virulence causes new waves of COVID-19 morbidity. The virus variability can cause the reduction of the vaccination effectiveness. In this regard, it is important to study the dynamics of post-vaccination immunity, its features in various population groups, as well as the relationship between post-infectious and post-vaccination immunity. The study continues a series of researches of the features of SARS-CoV-2-specific immunity in COVID-19 convalescents and recipients of the <<Sputnik V>> vaccine. The aim of the study - assessment of the intensity of the SARS-CoV-2-specific immune response in different age groups of people passed COVID-19 and subsequently vaccinated with <<Sputnik V>>. Material and methods. With the help of EIA, the level of IgG antibodies to S-antigen and N-antigen of SARS-CoV-2 was studied in 155 samples of blood sera of individuals (men and women) aged 18 to 70 years who passed COVID-19 and after 6 month of recovery underwent a full course of vaccination with <<Sputnik V>>. Samples from individuals of the following age groups were examined: from 18 to 35, from 35 to 45, from 45 to 55, from 55 to 65, from 65 to 70 years. Results. In all the examined age groups of individuals passed COVID-19 and then vaccinated with <<Sputnik V>>, there was a high level of IgG antibodies to SARS-CoV-2 S-protein (positivity coefficient 8.1 and higher). The level of IgG antibodies to the N-protein in more than half of the cases was lower than positive values among all the subjects. Conclusion. The study showed that individuals passed COVID-19 and then vaccinated with <<Sputnik V>>, regardless of age, have intense post-vaccination humoral immunity. Copyright © 2022 Meditsina Publishers. All rights reserved.
ABSTRACT
Introduction. Mass vaccination of the population against SARS-CoV-2 in Russia and abroad has been going on for more than 2 years. Various types of vaccines are used for vaccination (vector vaccines, RNA vaccines, whole-virion vaccines). The first in the world was registered the Russian vector vaccine «Gam-COVID-Vac» («Sputnik V»), which is widely used in our country, as well as in many other countries of the world. An important area of research is the monitoring of the parameters of the vaccine-induced immune response their analysis in relation to the characteristics of the immune response caused by SARSCoV-2 infection/COVID-19. Such studies are important both for assessing the intensity and duration of post-vaccination immunity, and for improving strategies for immunoprophylaxis and immunotherapy of coronavirus infection. The article presents the results of a study of the humoral immune response in patients with COVID-19 and vaccinated with «Sputnik V» in the period from autumn 2020 till the present time. The aim of the work - a comparative study of the humoral immune response to SARSCoV-2 infection and vaccination against COVID-19. Material and methods. The content of antibodies against SARS-CoV-2 S- and N-proteins was studied in 449 blood serum samples of men and women (age 25-65 years). 5 groups of samples were formed: suffered from COVID-19 of mild and moderate severity, at different times after recovery (262 samples);immunized with the «Sputnik V» vaccine, at different times after injection of the 2nd component of «Sputnik V» (104 samples);suffered from COVID-19 of mild and moderate severity, and then vaccinated with «Sputnik V» (53 samples);vaccinated with «Sputnik V», and then suffered with COVID-19 (12 samples);revaccinated with the vaccine «Sputnik Light» (18 samples). Results. To assess the content of IgG antibodies to S-protein and to N-protein of SARSCoV-2 in human blood sera, an EIA diagnostic system was developed further certified by the Ministry of Health of Russian Federation. In people suffered COVID-19 in 90 % of cases the positive levels of IgG antibodies to SARS-CoV-2 S-protein persist 9 months after recovery, while the proportion of potential plasma donors and material for obtaining intravenous immunoglobulin with a high content of IgG antibodies to S-protein 1 month after the disease is 20 %. In 76 % of people vaccinated with «Sputnik V» high levels of IgG antibodies to S-protein are detected within 6 months after the course of vaccination. The content of IgG antibodies to S-protein in the blood sera of persons suffered COVID-19, and then 6 months after recovery vaccinated with the 1st component of the vaccine «Sputnik V» in 100 % of cases was high with a positivity coefficient above 8.1, regardless of the initial value, already on 7 and 21 days after injection. In persons vaccinated with «Sputnik V» and then passed COVID-19, a high content of S-specific IgG antibodies is observed in 100 % of cases. The examination of vaccinated persons who underwent revaccination with «Sputnik Light» showed a 100 % high level of antibodies against S-protein. Conclusion. The developed test system may be suitable for assessing the content of IgG antibodies to SARS-CoV-2 antigens in COVID-19 patients, vaccinated and revaccinated. The performed study demonstrated that there is a intensive post-vaccination immunity for 6 months and post-infectious immunity for 9 months.