Neutralization of SARS-CoV-2 variants by convalescent and BNT162b2 vaccinated serum

Here, the authors show that neutralization of human sera from both BNT162b2 vaccine recipients and from convalescent COVID-19 patients is less efficient against SARS- CoV-2 variants B.1.1.7 and B.1.351 and negatively associated with patient age. SARS-CoV-2 and its variants continue to infect hundreds of thousands every day despite the rollout of effective vaccines. Therefore, it is essential to understand the levels of protection that these vaccines provide in the face of emerging variants. Here, we report two demographically balanced cohorts of BNT162b2 vaccine recipients and COVID-19 patients, from which we evaluate neutralizing antibody titers against SARS-CoV-2 as well as the B.1.1.7 (alpha) and B.1.351 (beta) variants. We show that both B.1.1.7 and B.1.351 are less well neutralized by serum from vaccinated individuals, and that B.1.351, but not B.1.1.7, is less well neutralized by convalescent serum. We also find that the levels of variant-specific anti-spike antibodies are proportional to neutralizing activities. Together, our results demonstrate the escape of the emerging SARS-CoV-2 variants from neutralization by serum antibodies, which may lead to reduced protection from re-infection or increased risk of vaccine breakthrough.

Automated summary

The study shows that serum from BNT162b2 vaccine recipients and convalescent COVID-19 patients has lower neutralization efficiency against SARS-CoV-2 variants B.1.1.7 and B.1.351, and this is negatively associated with patient age. The emerging SARS-CoV-2 variants are found to escape neutralization by serum antibodies, potentially leading to increased risk of reinfection or vaccine breakthrough.