Abstract
As existing vaccines fail to completely prevent COVID-19 infections or community transmission, there is an unmet need for vaccines that can better combat SARS-CoV-2 variants of concern (VOC). We previously developed highly thermo-tolerant monomeric and trimeric receptor-binding domain derivatives that can withstand 100 °C for 90 min and 37 °C for four weeks and help eliminate cold-chain requirements. We show that mice immunised with these vaccine formulations elicit high titres of antibodies that neutralise SARS-CoV-2 variants VIC31 (with Spike: D614G mutation), Delta and Omicron (BA.1.1) VOC. Compared to VIC31, there was an average 14.4-fold reduction in neutralisation against BA.1.1 for the three monomeric antigen-adjuvant combinations and a 16.5-fold reduction for the three trimeric antigen-adjuvant combinations; the corresponding values against Delta were 2.5 and 3.0. Our findings suggest that monomeric formulations are suitable for upcoming Phase I human clinical trials and that there is potential for increasing the efficacy with vaccine matching to improve the responses against emerging variants. These findings are consistent with in silico modelling and AlphaFold predictions, which show that, while oligomeric presentation can be generally beneficial, it can make important epitopes inaccessible and also carries the risk of eliciting unwanted antibodies against the oligomerisation domain.
Keywords: AlphaFold; COVID-19; Omicron; SARS-CoV-2; biomolecular modelling; receptor-binding domain (RBD); thermotolerant vaccine; vaccine equity; vaccine matching; variants of concern (VOC).
【저자키워드】 COVID-19, SARS-CoV-2, omicron, Receptor-binding domain (RBD), vaccine equity, biomolecular modelling, AlphaFold, thermotolerant vaccine, vaccine matching, variants of concern (VOC)., 【초록키워드】 Efficacy, Vaccine, antibody, VoC, SARS-CoV-2 variant, variants of concern, Delta, risk, in silico, omicron, variants, Epitopes, D614G mutation, Receptor-binding domain, COVID-19 infection, SARS-CoV-2 variants, mice, community transmission, epitope, neutralisation, Combination, phase, unmet need, reduction, COVID-19 infections, domain, average, help, titre, derivative, Prevent, human clinical trial, trimeric, IMPROVE, elicit, reduction in, responses against, inaccessible, monomeric, neutralise, 【제목키워드】 Delta, Thermotolerant,