Cross-neutralization of SARS-CoV-2 B.1.1.7 and P.1 variants in vaccinated, convalescent and P.1 infected

Abstract

Objectives : The emergence of new variants of concern (VOCs) of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) around the world significantly complicated the exit from Coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to evaluate the serum neutralizing activity of three cohorts. Methods : BNT162b2 -elicited serum (N=103), candidates as hyper-immune plasma donors (N=90) and patients infected with the SARS-CoV-2 P.1 variant (N=22) were enrolled. Three strains of SARS-CoV-2 have been tested: 20A.EU1, B.1.1.7 (alpha) and P.1 (gamma). Neutralizing antibodies (NT-Abs) titers against SARS-CoV-2 were evaluated. Results : B.1.1.7 and P.1 are less efficiently neutralized by convalescent wild-type infected serums if compared to 20A.EU1 strain (mean titer 1.6 and 6.7-fold lower respectively). BNT162b2 vaccine-elicited human sera show an equivalent neutralization potency on the B.1.1.7 but it is significantly lower for the P.1 variant (mean titer 3.3-fold lower). Convalescent P.1 patients are less protected from other SARS-CoV-2 strains with an important reduction of neutralizing antibodies against 20A.EU1 and B.1.1.7, about 12.2 and 10.9-fold, respectively. Conclusions : BNT162b2 vaccine confers immunity against all the tested VOCs, while previous SARS-CoV-2 infection may be less protective.

Determinants of early antibody responses to COVID-19 mRNA vaccines in exposed and naive healthcare workers

“…We have detected a 6.3% vaccine breakthrough among fully vaccinated participants in between 15 and 189 days post second dose, probably related to the fifth wave of the pandemic, mostly caused by the Delta variant. Here, we have not detected major differences in the IgG and IgA responses between any of the VoCs tested and the wild-type S, in contrast to other studies reporting diminished sensitivity of neutralizing antibodies against the Beta and Gamma variants [27,28,[30][31][32][33].…”

“…In contrast, Beta (B. 1.351) and Gamma (P.1), first identified in South Africa and Brazil, respectively, have decreased sensitivity to neutralizing antibodies elicited by vaccination [27,28,[30][31][32][33], but previous exposure induces higher cross-reactivity to variants [4,9]. More recently, the Delta variant, which also presents mutations in S, was identified in India and quickly spread over the world, and early data show that it may have an even lower sensitivity to convalescent and vaccine induced antibodies [34,35].…”

BNT162b2 SARS-CoV-2 Vaccination Elicits High Titers of Neutralizing Antibodies to Both B.1 and P.1 Variants in Previously Infected and Uninfected Subjects

“…The characteristics of the antigenicity of the P.1 variant are not completely known [35]: this fact and the different study designs, viral components tested (strain isolated from a clinical sample or generated mutant, as in Chang et al [36]), and commercial or in-house methods used to evaluate different kinds of antibody titers may explain the multifaceted response to the P.1 variant with respect to other SARS-CoV-2 strains. Gidari et al [17] described a post-vaccinal NtAb titer to B1 and P.1 specular to ours, and sera from vaccinated individuals showed a significant loss of neutralizing activity against P.1 but the impact was lower than that against B.1.351 [24,25,37]: these data underline the need to include SARS-CoV-2 viral sequencing of PCR-positive COVID-19 subjects in the diagnostic workflow because variant diffusion may reduce vaccine efficacy.…”

SARS-CoV-2 Delta (B.1.617.2) Variant: A Unique T478K Mutation in Receptor Binding Motif (RBM) of Spike Gene

“…1C ). Unfortunately, SARS-CoV-2 γ variant has few reports compared to other SARS-CoV-2 variant of concern ( 46 47 ).…”

“…Most studies of SARS-CoV-2 α and β variant of concern performed in EU and US whereas limited studies were conducted with SARS-CoV-2 viral vaccine, which was used widely in China, Southeast Asia, and South America ( Fig. 2A ) ( 40 46 56 57 58 ). Several reports attempted to study the impact of SARS-CoV-2 variants on the susceptibility of monoclonal Abs.…”