SARS-CoV-2 is the underlying cause for the COVID-19 pandemic. Like most enveloped RNA viruses, SARS-CoV-2 uses a homotrimeric surface antigen to gain entry into host cells. Here we describe S-Trimer, a native-like trimeric subunit vaccine candidate for COVID-19 based on Trimer-Tag technology. Immunization of S-Trimer with either AS03 (oil-in-water emulsion) or CpG 1018 (TLR9 agonist) plus alum adjuvants induced high-levels of neutralizing antibodies and Th1-biased cellular immune responses in animal models. Moreover, rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important new platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.
The Omicron variant of SARS-COV-2 (GISAID GRA clade [B.1.1.529, BA.1 and BA.2]) is now the single dominant Variant of Concern (VOC). The high number of mutations in the Omicron Spike (S) protein promotes humoral immunological escape. Although a third homologous boost with S, derived from the ancestral strain, was able to increase neutralizing antibody titers and breadth including to Omicron, the magnitude of virus neutralization could benefit from further optimization. Moreover, combining SARS-COV-2 strains as additional valences may address the current antigenicity range occupied by VOCs. Using Trimer-TagTM platform we have previously demonstrated phase 3 efficacy and safety of a prototypic vaccine SCB-2019 in the SPECTRA trial and have submitted applications for licensure. Here, we successfully generated a bivalent vaccine candidate including both Ancestor and Omicron variant S-proteins. Preclinical studies demonstrate this SARS-CoV-2 bivalent S-Trimer subunit vaccine elicits high titers of neutralizing antibodies against all VOCs, with markedly enhanced Omicron specific neutralizing antibody responses.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.