Immunogenicity and Efficacy of Monovalent and Bivalent Formulations of a Virus-Like Particle Vaccine against SARS-CoV-2
Matthew D. Resch, Ke Wen, Ryan Mazboudi, Hannah Mulhall Maasz, Mirjana Persaud, Kaitlyn Garvey, Leslie Gallardo, Paul Gottlieb, A. Alimova, Reza Khayat, Jorge Morales, Helle Bielefeldt‐Ohmann, Richard A. Bowen, Jose M. Galarza
Abstract
Virus-like particles (VLPs) offer great potential as a safe and effective vaccine platform against SARS-CoV-2, the causative agent of COVID-19. Here, we show that SARS-CoV-2 VLPs can be generated by expression of the four viral structural proteins in a mammalian expression system. Immunization of mice with a monovalent VLP vaccine elicited a potent humoral response, showing neutralizing activity against multiple variants of SARS-CoV-2. Subsequent immunogenicity and efficacy studies were performed in the Golden Syrian hamster model, which closely resembles the pathology and progression of COVID-19 in humans. Hamsters immunized with a bivalent VLP vaccine were significantly protected from infection with the Beta or Delta variant of SARS-CoV-2. Vaccinated hamsters showed reduced viral load, shedding, replication, and pathology in the respiratory tract. Immunized hamsters also showed variable levels of cross-neutralizing activity against the Omicron variant. Overall, the VLP vaccine elicited robust protective efficacy against SARS-CoV-2. These promising results warrant further study of multivalent VLP vaccines in Phase I clinical trials in humans.