Infection and vaccine-induced antibody binding and neutralization to the B.1.351 SARS-CoV-2 variant Edara et al.

The emergence of SARS-CoV-2 variants with mutations in the spike protein is raising concerns about the efficacy of infection- or vaccine-induced antibodies. We compared antibody binding and live virus neutralization of sera from naturally infected and Moderna vaccinated individuals against two SARS-CoV-2 variants, B.1 containing the spike mutation D614G and the emerging B.1.351 variant containing additional spike mutations and deletions. Sera from acutely-infected and convalescent COVID-19 patients exhibited a 3-fold reduction in binding antibody titers to the B.1.351 variant receptor binding domain of the spike protein and a 3.5-fold reduction in neutralizing antibody titers against SARS-CoV-2 B.1.351 variant compared to the B.1 variant. Similar results were seen with sera from Moderna vaccinated individuals. Despite reduced antibody titers against the B.1.351 variant, sera from infected and vaccinated individuals containing polyclonal antibodies to the spike protein could still neutralize SARS-CoV-2 B.1.351, suggesting that protective humoral immunity may be retained against this variant.

SARS-CoV-2病毒突变型刺突蛋白的出现，引发了对其感染或疫苗接种所诱导的抗体效力的担忧。本研究对比了自然感染者和Moderna疫苗接种者血清中抗体与两种SARS-CoV-2变异株（B.1型含有D614G刺突突变以及新出现的B.1.351变异株，后者包含额外的刺突突变和缺失）的抗体结合和活病毒中和能力。急性感染和康复期COVID-19患者的血清在B.1.351变异株刺突蛋白受体结合域的抗体结合滴度上呈现出3倍降低，在针对SARS-CoV-2 B.1.351变异株的中和抗体滴度上降低了3.5倍，与B.1型变异株相比。Moderna疫苗接种者的血清也呈现了相似的结果。尽管对B.1.351变异株的抗体滴度降低，但含有针对刺突蛋白的多克隆抗体的感染者和疫苗接种者血清仍能中和SARS-CoV-2 B.1.351变异株，这表明针对此变异株的保护性体液免疫可能得以保留。