Memory B cell and humoral responses elicited by Sputnik V in naïve and COVID-19-recovered vaccine recipients

Abstract

The development of effective vaccines against SARS-CoV-2 remains a global health priority. Despite extensive use, the effects of Sputnik V on B cell immunity need to be explored in detail. We show that B memory cell (MBC) and antibody responses to Sputnik V were heavily dependent on whether the vaccinee had a history of SARS-CoV-2 infection or not. In vitro stimulated MBCs from previously infected recipients of Sputnik V secreted a significant amount of anti-RBD IgG both on days 28 and 85 from the beginning of vaccination. These antibodies demonstrated robust neutralization of the Wuhan Spike-pseudotyped lentivirus. In the naïve group of vaccinees, the level of anti-RBD IgG secretion was five- to- six-fold reduced compared to that of the recovered group, and maximum virus neutralization (Wuhan spike) was achieved only on day 85. Sera from all the recovered and most naïve Sputnik V recipients were neutralizing against the ancestral Wuhan and mutant B.1.351 viruses. Thus, our in-depth analysis of MBC responses in Sputnik V vaccinees complements traditional serological approaches and may provide important outlook into future B cell responses upon re-encounter with the emerging variants of SARS-CoV-2.

A Retrospective Study on the Gam-COVID-Vac (Sputnik V) COVID-19 Vaccine Short-Term Efficacy and Side Effects in Iranian Healthcare Providers

“…It has even been reported that a single dose of Sputnik V can significantly increase the antibody level in vaccine recipients without a history of COVID-19 (10). Also, the induction of memory B cell responses in Sputnik V was promising (12). Regardless of the high efficacy of the Sputnik V against the wild-type SARS-CoV-2 and the alpha variant (VOC 1, B.1.1.7), there are some concerns about the efficacy of the vaccine in dealing with the emerged variants, such as beta or B.…”

Clonal diversity determines persistence of SARS-CoV-2 epitope-specific T cell response

“…The levels of circulating binding and neutralizing antibodies are highly variable between individuals, but in most patients, humoral response decays over the first 6-8 months post-infection (Dan et al, 2021;Sherina et al, 2021, Wheatley et al 2021. It has been shown that SARS-CoV-2-specific memory B cells (Sherina et al, 2021;Byazrova et al, 2021a;Byazrova et al, 2021b;Sokal et al, 2021;Marcote et al, 2021) and T cells are maintained in COVID-19 convalescent patients at least for 6-8 months (Dan et al, 2021;Sherina et al, 2021;Zuo et al, 2020;Bilich et al, 2021), and the latest reports further extend this margin to up to 10-15 months (Jung et al, 2021, Marcote et al, 2021. Although the numbers of circulating T cells decrease over time (Wheatley et al, 2021;Marcotte et al, 2021), these cells retain the ability to secrete cytokines (Kang et al, 2021) and to expand (Rodda et al, 2021) upon re-stimulation with the appropriate antigen.…”