AUTHOR=Boudewijns Robbert , Pérez Patricia , Lázaro-Frías Adrián , Van Looveren Dominique , Vercruysse Thomas , Thibaut Hendrik Jan , Weynand Birgit , Coelmont Lotte , Neyts Johan , Astorgano David , Montenegro Dolores , Puentes Eugenia , Rodríguez Esteban , Dallmeier Kai , Esteban Mariano , García-Arriaza Juan TITLE=MVA-CoV2-S Vaccine Candidate Neutralizes Distinct Variants of Concern and Protects Against SARS-CoV-2 Infection in Hamsters JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.845969 DOI=10.3389/fimmu.2022.845969 ISSN=1664-3224 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.