Evaluation of the Gam-COVID-Vac and vaccine-induced neutralizing response against SARS-CoV-2 lineage P.1 variant in an Argentinean cohort

Abstract

We evaluated humoral immune-response elicited by Sputnik-V by measuring anti-Spike (S) IgG antibodies (Abs) and neutralizing antibodies (NAb) prior to, 14 and 42 days after-vaccination. The safety and disease rates among vaccinated individuals were also evaluated. Since SARS-CoV-2 lineage P.1 is rapidly spreading in Argentina, virus-neutralizing activity of Sputnik-V-elicited and infection-elicited NAb faced to P.1 were also assessed. A total of 285 participants were recruited; all reported good tolerance, without any severe adverse event. Nine COVID-19 cases were confirmed in fully vaccinated individuals and viable P.1 variant was successfully isolated from one of them. At day 42, 99.65% of the individuals had anti-S IgG; however, 23.15% had not detectable NAbs. Significantly higher neutralization potency against WT compared to P.1 (p < 0·001) was observed. Some samples failed to neutralize P.1, mainly among vaccinated-naїve subjects; however, no significant differences were observed among previously infected-vaccinated individuals. Our results corroborated that Sputnik-V is safe and induces an efficient humoral immune response, although not all immunized subjects develop Nabs. Herein, we show for the first time, evidence of infectious SARS-CoV-2 shedding from Sputnik-V fully vaccinated individuals, by the isolation of viable virus from the nasopharyngeal swab of one participant of our study, 139 days after receiving the second dose. Thereby, we provide evidence indicating that the vaccine might avoid severe forms of COVID-19 but does not prevent infection nor prevents transmission from a fully vaccinated individual.

Keywords: COVID-19; Neutralizing antibodies; SARS-CoV-2; SARS-CoV-2 lineage P.1; Sputnik-V; Variants of concern.

Fig. 1

Neutralizing antibodies in a cohort of individuals vaccinated with Sputnik V in Córdoba City, Argentina. Results in a Cohort of 285 subjects vaccinated with Sputnik V. 1a. Distribution of NAb titres in basal samples, at days 14 and 42 after vaccination, respectively. 1b. Distribution of NAb titres in I: Individuals with history of previous infection, basal time; II: Individuals without previous SARS-CoV-2 infection (naïve), 14 days post vaccination; III: Individuals with history of previous infection, 14 days post vaccination; IV: Individuals without previous infection (naïve), 42 days post vaccination, V: Individuals with history of previous infection, 42 days post vaccination. 1c. Geometric Mean Titres of neutralizing antibodies (GMT) in I, II, III, IV, and V groups. Means with a common letter are not significantly different (Kruskal Wallis test).

Fig. 2

Neutralization of WT and P.1 by vaccine-elicited and COVID-19 convalescent plasma in Córdoba City, Argentina. Comparison of neutralizing antibody properties against wild type (WT) B.1 (hCoV-19/Argentina/PAIS-G0001/2020, GISAID ID: EPI_ISL_499083) (WT) and SARS-CoV-2 Lineage P.1 (hCoV19/Argentina/PAIS-G0234/2021, GSAID ID: EPI_ISL_2037442)(P.1). 1- Group A: Individuals recovered from SARS-CoV-2 WT natural infection, 2- Group B: Individuals recovered from SARS-CoV-2 WT natural infection that received one or two doses of Sputnik-V vaccine, and 3-Group C: Individuals without previous infection, vaccinated with one or two doses of Sputnik-V vaccine. 2a. Results of the analysis of neutralizing antibodies GMTs against WT and P.1in each group performed with mixed linear models and Tukey’s post-hoc test. Means with a common letter are not significantly different.2b. Distribution of NAb titres against WT and P.1 lineages in each group. 2c. Neutralizing GMTs are shown as pair wise connected against the WT and P.1 lineages in the categorized Groups A, B, and C. P values obtained by the Wilcoxon paired test.