PROS1 and infection: Here, we report that vaccination with a prefusion, stabilized SARS-CoV-2 S protein (ST) expressed by recombinant MVA (MVA-ST) elicits a better humoral immune response and provides protection upon SARS-CoV-2 BavPat1 challenge infection compared with the original recombinant MVA vaccine delivering the nonmodified SARS-CoV-2 S antigen (MVA-S).