The levels of SARS-CoV-2 IgG antibody and cytokine profile in blood serum of young people during the COVID-19 pandemic

During the COVID-19 pandemic, many issues remained unclear, i.e., those related to features of immune response in the disease, vaccination, and development of post-COVID syndrome, or its atypical forms. Optimal and effective vaccination strategies against respiratory viral infections in the “post-COVID era” have not been determined so far. The variety of vaccines, vaccination history, risk factors, as well as joining of COVID-19 to the spectrum of seasonal infections significantly influence the initial immunological profile of various population groups. The study group included 80 young men aged 19 years living in closed communities. Blood sampling was carried out in 2022, 9 months after the course of vaccination with the Sputnik V vaccine. The levels of pro- and anti-inflammatory cytokines (IL-1β, IL-4, IL-6, IL-8, IL-10, IL-17, IFNγ, TNFα), as well as IgM and IgG antibodies to SARS-CoV-2 were measured in venous blood sera. The results were processed by Microsoft Excel, R-Statistics, SPSS 22. The normality of distribution for quantitative data was assessed by the Kolmogorov–Smirnov test. Quantitative data are presented as Me (Q 0.25 -Q 0.75 ); qualitative, in the form of n (%). Spearman’s correlation coefficient was used to determine statistical significance. The average level of SARS-CoV-2 IgG antibodies 9 months after vaccination exceeded the protective level by more than 3 times. Comparisons of cytokine levels and SARS-CoV-2 IgG antibodies have yielded various findings. In group 1 with SARS-CoV-2 IgG antibodies < 150 BAU/mL, the levels of pro-inflammatory cytokines (IL-1β, TNFα, IL-6, IL-8) were > 2-fold higher than in group 2 with SARS-CoV-2 IgG antibodies ranging from 150 to 500 BAU/mL. Moreover, IL-10 level was 5 times higher in group 1 compared to group 2. The level of IL-10 was significantly higher (4 times) in group 3 with SARS-CoV-2 IgG antibody levels of > 500 BAU/mL. In our opinion, there are many factors influencing the immune response, thus requiring a personalized approach to vaccination by taking into account the initial immune state. To optimize booster vaccination, the initial antibody levels should be checked, and immunological indices may be used in order to assess the necessity of re-vaccination.