Abstract
Coronavirus disease 2019 (COVID-19) vaccination regimens contribute to limiting the spread of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2). However, the emergence and rapid transmission of the SARS-CoV-2 variant Omicron raise a concern about the efficacy of the current vaccination strategy. Here, we expressed monomeric and dimeric receptor-binding domains (RBDs) of the spike protein of prototype SARS-CoV-2 and Omicron variant in E. coli and investigated the reactivity of anti-sera from Chinese subjects immunized with SARS-CoV-2 vaccines to these recombinant RBDs. In 106 human blood samples collected from 91 participants from Jiangxi, China, 26 sera were identified to be positive for SARS-CoV-2 spike protein antibodies by lateral flow dipstick (LFD) assays, which were enriched in the ones collected from day 7 to 1 month post-boost (87.0%) compared to those harvested within 1 week post-boost (23.8%) ( P < 0.0001). A higher positive ratio was observed in the child group (40.8%) than adults (13.6%) ( P = 0.0073). ELISA results showed that the binding activity of anti-SARS-CoV-2 antibody-positive sera to Omicron RBDs dropped by 1.48- to 2.07-fold compared to its homogeneous recombinant RBDs. Thus, our data indicate that current SARS-CoV-2 vaccines provide restricted humoral protection against the Omicron variant.
Keywords: COVID-19; RBD; binding activity; omicron; spike protein.
【저자키워드】 COVID-19, omicron, spike protein., RBD, binding activity, 【초록키워드】 coronavirus disease, SARS-CoV-2, Coronavirus disease 2019, Efficacy, vaccination, antibody, variant, SARS-CoV-2 variant, Transmission, SARS-CoV-2 vaccines, severe acute respiratory syndrome coronavirus-2, severe acute respiratory syndrome Coronavirus, omicron, anti-SARS-CoV-2, ELISA, SARS-CoV-2 vaccine, Spike protein, Spread, lateral flow, China, Severe acute respiratory syndrome, Receptor-binding domain, anti-SARS-CoV-2 antibody, sera, SARS-CoV-2 spike protein, Omicron variant, binding, RBDs, binding activity, Vaccination strategy, humoral, regimen, be positive, acute respiratory syndrome, LFD, E. coli, subject, acute respiratory syndrome coronavirus-2, blood sample, Chinese, participant, prototype, positive, immunized, raise, collected, assays, investigated, contribute, the spike protein, expressed, homogeneous, reactivity, dimeric, dropped, monomeric, the SARS-CoV-2, 【제목키워드】 Vaccine, serum, domain,