Increased neutralization of SARS-CoV-2 Delta variant after heterologous ChAdOx1 nCoV-19/BNT162b2 versus homologous BNT162b2 vaccination

Abstract

Heterologous SARS-CoV-2 vaccine approaches with a second mRNA-based vaccine have been favored in the recommendations of many countries over homologous vector-based ChAdOx1 nCoV-19 vaccination after reports of thromboembolic events and lower efficacy of this regimen. In the middle of 2021, the SARS-CoV-2 Delta variant of concern (VoC) has become predominant in many countries worldwide. Data addressing the neutralization capacity of a heterologous ChAdOx1 nCoV-19/mRNA-based vaccination approach against the Delta VoC in comparison to the widely used homologous mRNA-based vaccine regimen are limited. Here, we compare serological immune responses of a cohort of ChAdOx1 nCoV-19/BNT162b2 vaccinated participants with those of BNT162b2/BNT162b2 vaccinated ones and show that neutralization capacity against the Delta VoC is significantly increased in sera of ChAdOx1 nCoV-19/BNT162b2 vaccinated participants. This overall effect can be attributed to ChAdOx1 nCoV-19/BNT162b2 vaccinated women, especially those with more severe adverse effects leading to sick leave following second immunization.

Vaccination COVID-19 : technologies vaccinales, efficacité en vie réelle et spécificités

“…Considérant maintenant la réactogénicité, le schéma hétérologue est globalement bien toléré et sûr [ 29 , 32 ]. D'autre part, ce dernier offre une protection contre les variants préoccupants actuels comme le suggèrent les données sur la neutralisation contre les variants Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), et plus récemment Delta (B.1.617.2) et Omicron (B.1.1.529) [33] , [34] , [35] .…”

Targeted escape of SARS-CoV-2 in vitro from monoclonal antibody S309, the precursor of sotrovimab

“… Susceptibility of SARS-CoV-2 variants to inhibition of endocytosis and fusion by aloxistatin and camostat, respectively. CaCo-2 and HEK293T cells were infected with (A, B) a SARS-CoV-2 Delta strain ( 39 ), (C, D) wild-type virus (CA) used as input for selection of S309-resistant strains, and mutant strains with (E, F) R346S and (G, H) R346S+P337L (7S1), using a multiplicity of infection of 0.05. Cells were propagated in the presence of the endocytosis inhibitor aloxistatin, the fusion inhibitor camostat or both in a 1:1 ratio (mix) at concentrations of the individual inhibitors between 0.024-100 µM.…”