Main study: •Binding antibody concentrations to SARS CoV-2 S protein as measured by ELISA 28 days after vaccination •NI will be demonstrated in terms of humoral immune response expressed by the GMCs of S-ELISA, 28 days post-dose 1, using a NI margin of 2/3 for the GMC ratio (GMC 9x10^10 vp, 7x10^10 vp, 3.5x10^10 vp, 2.5x10^10 vp, or 1.25x10^10 vp/GMC 5x10^10 vp) •Binding antibody concentrations to SARS CoV-2 S protein as measured by ELISA 14 days after vaccination 2 •NI will be demonstrated in terms of humoral immune response expressed by the GMCs of S-ELISA, 14 days post-dose 2 (9x10^10 vp, 7x10^10 vp, 3.5x10^10 vp, 2.5x10^10 vp, or 1.25x10^10 vp) and 28 days post-dose 1 or 14 days post-dose 2 (5x10^10 vp), using a NI margin of 2/3 for the GMC ratio (GMC 9x10^10 vp, 7x10^10 vp, 3.5x10^10 vp, 2.5x10^10 vp, or 1.25x10^10 vp/GMC 5x10^10 vp)

Main study: •Binding antibody concentrations to SARS CoV-2 S protein as measured by ELISA 28 days after vaccination •NI will be demonstrated in terms of humoral immune response expressed by the GMCs of S-ELISA, 28 days post-dose 1, using a NI margin of 2/3 for the GMC ratio (GMC 9x10^10 vp, 7x10^10 vp, 3.5x10^10 vp, 2.5x10^10 vp, or 1.25x10^10 vp/GMC 5x10^10 vp) •Binding antibody concentrations to SARS CoV-2 S protein as measured by ELISA 14 days after vaccination 2 •NI will be demonstrated in terms of humoral immune response expressed by the GMCs of S-ELISA, 14 days post-dose 2 (9x10^10 vp, 7x10^10 vp, 3.5x10^10 vp, 2.5x10^10 vp, or 1.25x10^10 vp) and 28 days post-dose 1 or 14 days post-dose 2 (5x10^10 vp), using a NI margin of 2/3 for the GMC ratio (GMC 9x10^10 vp, 7x10^10 vp, 3.5x10^10 vp, 2.5x10^10 vp, or 1.25x10^10 vp/GMC 5x10^10 vp)