Prior to study entry the subject got vaccinated with a regimen not included in the above list. Last anti-SARS-CoV-2 vaccine dose administered less than one month prior to study entry. Vaccination against a disease other than COVID-19 within 2 weeks prior to study entry. Only exception: Influenza vaccination which is allowed at any time. Current immunosuppressive therapy, for example continuous glucocorticosteroid treatment equivalent to >10 mg/day prednisolone. Subject participates or participated in Part A of this trial.

Prior to study entry the subject got vaccinated with a regimen not included in the above list. Last anti-SARS-CoV-2 vaccine dose administered less than one month prior to study entry. Vaccination against a disease other than COVID-19 within 2 weeks prior to study entry. Only exception: Influenza vaccination which is allowed at any time. Current immunosuppressive therapy, for example continuous glucocorticosteroid treatment equivalent to >10 mg/day prednisolone. Subject participates or participated in Part A of this trial.

Primary vaccination performed with different vaccine products as sole (e.g. COVID-19 Vaccine Janssen) or, 1st and 2nd vaccination doses (heterologous vaccination scheme). Any contraindication against any of the vaccines at time of enrolment including current SARS-CoV-2 infection or proven in the last 3 months. Immunocompromised status.

Primary vaccination performed with different vaccine products as sole (e.g. COVID-19 Vaccine Janssen) or, 1st and 2nd vaccination doses (heterologous vaccination scheme). Any contraindication against any of the vaccines at time of enrolment including current SARS-CoV-2 infection or proven in the last 3 months. Immunocompromised status.