COVID-19 mRNA vaccine induced antibody responses against three SARS-CoV-2 variants

TLDR

SARS‑CoV‑2 has circulated for over a year with many vaccine candidates, and the BNT162b2 mRNA vaccine elicits spike‑specific neutralizing antibodies, but the emergence of B.1.1.7 and B.1.351 variants raises concerns about reduced vaccine efficacy. After two doses, BNT162b2‑vaccinated individuals neutralize D614G and B.1.1.7 variants effectively, but neutralization of B.1.351 is reduced five‑fold, yet 92 % retain titers >20 and titres surpass those of recovered patients, indicating cross‑neutralization.

Abstract

Abstract As SARS-CoV-2 has been circulating for over a year, dozens of vaccine candidates are under development or in clinical use. The BNT162b2 mRNA COVID-19 vaccine induces spike protein-specific neutralizing antibodies associated with protective immunity. The emergence of the B.1.1.7 and B.1.351 variants has raised concerns of reduced vaccine efficacy and increased re-infection rates. Here we show, that after the second dose, the sera of BNT162b2-vaccinated health care workers (n = 180) effectively neutralize the SARS-CoV-2 variant with the D614G substitution and the B.1.1.7 variant, whereas the neutralization of the B.1.351 variant is five-fold reduced. Despite the reduction, 92% of the seronegative vaccinees have a neutralization titre of >20 for the B.1.351 variant indicating some protection. The vaccinees’ neutralization titres exceeded those of recovered non-hospitalized COVID-19 patients. Our work provides evidence that the second dose of the BNT162b2 vaccine induces cross-neutralization of at least some of the circulating SARS-CoV-2 variants.