ABNCoV2 Vaccine in SARS-CoV-2 (COVID-19) Seronegative and Seropositive Adult Subjects

An open label phase 2 trial to evaluate safety, tolerability and immunogenicity of the ABNCoV2 vaccine after intramuscular (IM) application. The trial will evaluate a homologous prime-boost regimen with 100 µg ABNCoV2 in initially seronegative adult subjects (Group 1), as determined by a qualitative test for SARS-CoV-2 antibodies, compared to a single boost vaccination with 100 µg (Group 2) or 50 µg (Group 3) ABNCoV2 in initially seropositive subjects, as defined by a positive qualitative test for SARS-CoV-2 antibodies and a history of SARS-CoV-2 vaccination or previous COVID-19 disease at least 90 days prior to planned trial vaccination.