MVA-CoV2-S Vaccine Candidate Neutralizes Distinct Variants of Concern and Protects Against SARS-CoV-2 Infection in Hamsters
Robbert Boudewijns, Patricia Pérez, Adrián Lázaro-Frías, Dominique Van Looveren, Thomas Vercruysse, Hendrik Jan Thibaut, Birgit Weynand, Lotte Coelmont, Johan Neyts, David Astorgano, Dolores Montenegro, Eugenia Puentes, Esteban Rodríguez, Kai Dallmeier, Mariano Estéban, Juan García‐Arriaza
Abstract
To control the coronavirus disease 2019 (COVID-19) pandemic and the emergence of different variants of concern (VoCs), novel vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed. In this study, we report the potent immunogenicity and efficacy induced in hamsters by a vaccine candidate based on a modified vaccinia virus Ankara (MVA) vector expressing a human codon optimized full-length SARS-CoV-2 spike (S) protein (MVA-S). Immunization with one or two doses of MVA-S elicited high titers of S- and receptor-binding domain (RBD)-binding IgG antibodies and neutralizing antibodies against parental SARS-CoV-2 and VoC alpha, beta, gamma, delta, and omicron. After SARS-CoV-2 challenge, MVA-S-vaccinated hamsters showed a significantly strong reduction of viral RNA and infectious virus in the lungs compared to the MVA-WT control group. Moreover, a marked reduction in lung histopathology was also observed in MVA-S-vaccinated hamsters. These results favor the use of MVA-S as a potential vaccine candidate for SARS-CoV-2 in clinical trials.