Efficacy of an unmodified bivalent mRNA vaccine against SARS-CoV-2 variants in female small animal models.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36781853.
- Also identified by DOI 10.1038/s41467-023-36110-1 and PMC identifier 9924835.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Combining optimized spike (S) protein-encoding mRNA vaccines to target multiple SARS-CoV-2 variants could improve control of the COVID-19 pandemic. We compare monovalent and bivalent mRNA vaccines encoding B.1.351 (Beta) and/or B.1.617.2 (Delta) SARS-CoV-2 S-protein in a transgenic mouse and a Wistar rat model. The blended low-dose bivalent mRNA vaccine contains half the mRNA of each respective monovalent vaccine, but induces comparable neutralizing antibody titres, enrichment of lung-resident memory CD8<sup>+</sup> T cells, antigen-specific CD4<sup>+</sup> and CD8<sup>+</sup> responses, and protects transgenic female mice from SARS-CoV-2 lethality. The bivalent mRNA vaccine significantly reduces viral replication in both Beta- and Delta-challenged mice. Sera from bivalent mRNA vaccine immunized female Wistar rats also contain neutralizing antibodies against the B.1.1.529 (Omicron BA.1 and BA.5) variants. These data suggest that low-dose and fit-for-purpose multivalent mRNA vaccines encoding distinct S-proteins are feasible approaches for extending the coverage of vaccines for emerging and co-circulating SARS-CoV-2 variants.
Medical subject headings
- COVID-19
- COVID-19 Vaccines
- SARS-CoV-2