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Engineering Antiviral Agents via Surface Plasmon Resonance
Published on: June 14, 2022
Reduced binding activity of vaccine serum to omicron receptor-binding domain
Mingzhi Li1, Shiqi Weng1, Quansheng Wang1
1Nanchang City Key Laboratory of Animal Virus and Genetic Engineering, Institute of Pathogenic Microorganism, College of Bioscience and Engineering, Jiangxi Agricultural University, Nanchang, China.
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.
Insights
Current COVID-19 vaccines show reduced effectiveness against the Omicron variant. Antibody responses were significantly lower when binding to Omicron’s spike protein receptor-binding domains compared to the original strain.
Area of Science:
- Immunology
- Virology
- Vaccinology
Background:
- Coronavirus disease 2019 (COVID-19) vaccines are crucial for controlling severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) spread.
- The emergence of the SARS-CoV-2 Omicron variant raises concerns about the sustained efficacy of existing COVID-19 vaccination strategies.
Purpose of the Study:
- To investigate the reactivity of sera from vaccinated Chinese individuals against prototype SARS-CoV-2 and Omicron variant receptor-binding domains (RBDs).
- To assess the impact of the Omicron variant on the humoral protection conferred by current SARS-CoV-2 vaccines.
Main Methods:
- Recombinant monomeric and dimeric RBDs of prototype SARS-CoV-2 and Omicron variant spike proteins were expressed in *E. coli*.
- Sera from 91 participants in Jiangxi, China, were tested for SARS-CoV-2 spike protein antibodies using lateral flow dipstick (LFD) assays.
- Enzyme-linked immunosorbent assay (ELISA) was used to measure the binding activity of positive sera to prototype and Omicron RBDs.
Main Results:
- Antibody positivity was significantly higher from 7 days to 1 month post-boost (87.0%) compared to within 1 week post-boost (23.8%).
- A higher antibody positive ratio was observed in children (40.8%) than in adults (13.6%).
- Sera from individuals vaccinated against SARS-CoV-2 showed a 1.48- to 2.07-fold decrease in binding activity to Omicron RBDs compared to prototype RBDs.
Conclusions:
- Current SARS-CoV-2 vaccines provide limited humoral protection against the Omicron variant.
- The study highlights the need for updated vaccine strategies to address the evolving SARS-CoV-2 variants.
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