Antibody neutralization to SARS-CoV-2 and variants after one year in Wuhan

Most COVID-19 patients can build effective humoral immunity against SARS-CoV-2 after recovery . However, it remains unknown how long the protection can maintain and how efficiently it can protect people from the reinfection of the emerging SARS-CoV-2 variants. Here we evaluated the sera from 248 COVID-19 convalescents around one year post-infection in Wuhan, the earliest epicenter of SARS-CoV-2. We demonstrated that the SARS-CoV-2 immunoglobulin G (IgG) maintains at a high level and potently neutralizes the infection of the original strain (WT) and the B.1.1.7 variant in most patients. However, they showed varying degrees of efficacy reduction against the other variants of concern (P.1, B.1.525, and especially B.1.351) in a patient-specific manner. Mutations in RBD including K417N, E484K, and E484Q/L452R (B.1.617) remarkably impair the neutralizing activity of the convalescents' sera. Encouragingly, we found that a small fraction of patients' sera showed broad neutralization potency to multiple variants and mutants, suggesting the existence of broadly neutralizing antibodies recognizing the epitopes beyond the mutation sites. Our results suggest that the SARS-CoV-2 vaccination effectiveness relies more on the timely re-administration of the epitope-updated vaccine than the durability of the neutralizing antibodies.