Alliance for Pandemic Preparedness

February 23, 2021

Reduced Binding and Neutralization of Infection- and Vaccine-Induced Antibodies to the B.1.351 (South African) SARS-CoV-2 Variant

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[Pre-print, not peer-reviewed] Antibodies collected from people who had been infected with SARS-CoV-2 or who had received the Moderna vaccine showed lower levels of binding to the SARS-CoV-2 B.1.351 variant (first described in South Africa) compared to the D614G variant that has been dominant globally. This effect was observed for antibodies from individuals with acute infection within 5-19 days post-symptom onset (n=19), recovering individuals through 8 months post-symptom onset (n=30), and individuals within 14 days of the 2nd dose of the Moderna vaccine (n=19). There was a 4.3-fold average reduction in IgG antibody titers to the B.1.351-derived receptor binding domain of the spike protein and 3.5-fold average reduction in neutralizing titers. Reduction in neutralizing titers was lowest among convalescent individuals at the 3-8 month timepoint (2.1-fold reduction), followed by vaccinated individuals (3.8-fold reduction). However, most sera from acutely infected (74%) and convalescent individuals (77% at 1-3 months and 85% at 1-3 months) and all sera from vaccinated individuals neutralized the SARS-CoV-2 B.1.351 variant in vitro.

Edara et al. (Feb 22, 2021). Reduced Binding and Neutralization of Infection- and Vaccine-Induced Antibodies to the B.1.351 (South African) SARS-CoV-2 Variant. Pre-print downloaded Feb 23 from https://doi.org/10.1101/2021.02.20.432046