Features of the functioning of B-2 lymphocytes in patients with common variable immune deficiency in post-vaccination immunity to SARS-CoV-2

   Objective: B-2 lymphocytes characteristic of patients with CVID in the process of forming a post-vaccination response to the peptide vaccine against SARS-CoV-2.   Materials and methods: 10 people with CVID diagnosis were included in the study among a cohort of patients with primary immunodeficiency under the supervision of the Research Institute and the Department of Clinical Immunology and allergology of Rostov State Medical University. For the immunoprophylaxis of COVID-19, a recombinant peptide vaccine was used, which was administered intramuscularly at a dose of 0.5 ml twice with an interval of 21 days. The parameters of the immune system were evaluated before vaccination, then 21 days after the first and second doses and 72 days after the first injection. Phenotypic characteristic of peripheral blood B cells was performed by cytofluoriometry flow method.   Results: before vaccination,  the number of memory B cells with a phenotypic option of switched and unswitched to antibody synthesis at the patients with CVID was lower than the control parameters of practically healthy donors. 21 days after the administration of the first dose, an increase in un-switched and switched memory B cells, plasma blasts, and a decrease in the proportion of B-regulatory lymphocytes were noted in relation to the initial values. 21 days after the second injection, an increase in the total pool of B-2 lymphocytes, naive B cells, switched memory B cells, plasma blasts were revealed. A month later, this tendency continued.   Conclusion: in the process of forming a post-vaccination response to the peptide vaccine against SARS-CoV-2 in patients with CVID, a transformation of the subpopulation composition of B lymphocytes was revealed, as well as in the form of an increase in the number of memory B2 lymphocytes.