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

Abstract

We aimed to investigate neutralizing antibody titers (NtAbT) to the P.1 and B.1 SARS-CoV-2 variants in a cohort of healthy health care workers (HCW), including 20 previously infected individuals tested at baseline (BLinf, after a median of 298 days from diagnosis) and 21 days after receiving one vaccine dose (D1inf) and 15 uninfected subjects tested 21 days after the second-dose vaccination (D2uninf). All the subjects received BNT162b2 vaccination. D1inf NtAbT increased significantly with respect to BLinf against both B.1 and P.1 variants, with a fold-change significantly higher for P.1. D1inf NtAbT were significantly higher than D2uninf NtAbT, against B.1 and P.1. NtAbT against the two strains were highly correlated. P.1 NtAbT were significantly higher than B.1 NtAbT. This difference was significant for post-vaccination sera in infected and uninfected subjects. A single-dose BNT162b2 vaccination substantially boosted the NtAb response to both variants in the previously infected subjects. NtAb titers to B.1 and P.1 lineages were highly correlated, suggesting substantial cross-neutralization. Higher titers to the P.1 than to the B.1 strain were driven by the post-vaccination titers, highlighting that cross-neutralization can be enhanced by vaccination.

Molecular characteristics, immune evasion, and impact of SARS-CoV-2 variants

“…The two mRNA vaccines, BNT162b2 and mRNA-1273, maintained equivalent protection efficacy against Alpha 327 – 331 Beta, 221 , 330 , 332 , 333 Gamma, 327 , 330 , 333 , 334 and Delta 221 , 327 , 330 , 335 – 337 variants in all major endpoints, with only a moderate decrease in protection against documented Beta variant infection. 338 For the adenovirus vaccine AZD1222, VE for Beta variant symptomatic infection was found to drop dramatically to 10.4% (95% CI: −76.8 to 54.8) in a prospective study performed in South Africa among 2026 participants, 328 while the protection against Alpha, 330 , 339 , 340 Gamma, 330 , 334 and Delta 339 , 341 – 343 variant was mostly retained.…”