Assessment of the humoral immune response and post-vaccination events when using various COVID-19 vaccines during the pandemic, taking into account the change of virus strains

Objective. To study the humoral immune response and evaluate the frequency of post-vaccination events when using various COVID-19 vaccines during the pandemic, taking into account the change in virus strains. Materials and Methods. The study of the immunogenicity and frequency of post-vaccination events during COVID-19 immunization using the vaccines Sputnik V, Sinopharm and Soberana Plus approved for use in the Republic of Belarus, as well as the vaccine BelKovidVak, was conducted. Results. According to the results of genotyping of SARS-CoV-2 strains in 2021, the majority of the samples (67.3%) were genovariants of B.1.617.2 (Delta) lines. In 2022 they accounted for 1.3% of samples. In 2022 93.5% of samples belonged to other genetic lines of the SARS-CoV-2 virus not related to B.1.1.529 and B.1.617.2. The highest concentration of IgG to SARS-CoV-2 was observed on the 90th day after administration of the BelKovidVak vaccine. In a study of the frequency of adverse events after primary immunization with Sputnik V (Gam-COVID-Vac) and Sinopharm (BBIBP-CorV) vaccines, 45% of participants had mild or moderate adverse events: soreness (74.1%) and redness (11.1%) at the site of injections, fever (40.7%), weakness (3.7%), headache (3.7%), swelling of the injection site (3.7%). Elevated body temperature was significantly more common (p<0.001) in the group vaccinated with Sputnik V. According to the BelKovidVak vaccine study, most of the adverse events fell into the categories of “Systemic disorders and injection site reactions”, “Nervous system disorders”, “Respiratory, thoracic and mediastinal disorders” and “Laboratory and instrumental data” of mild severity. Adverse events were noted in 37.8% of cases (p=0.02) after administration of the Soberana Plus vaccine (FINLAY-FR-1A). Soreness at the injection site was most often noted (67.3% of cases). Conclusion. COVID-19 vaccines have a beneficial safety profile and develop a humoral immune response that persists for several months.