Geometric mean of Anti-S IgG concentrations at each time point in a subset of participants;Geometric mean of SARS-CoV-2 serum neutralizing titers by Plaque reduction neutralization test (PRNT) at each time point in a subset of participants;Number of participants who experience a first episode of virologically-confirmed {reverse transcription polymerase chain reaction (RT-PCR) positive} case of COVID-19 of any severity;Percentage of participants reporting Serious adverse events or medically attended adverse events

Geometric mean of Anti-S IgG concentrations at each time point in a subset of participants;Geometric mean of SARS-CoV-2 serum neutralizing titers by Plaque reduction neutralization test (PRNT) at each time point in a subset of participants;Number of participants who experience a first episode of virologically-confirmed {reverse transcription polymerase chain reaction (RT-PCR) positive} case of COVID-19 of any severity;Percentage of participants reporting Serious adverse events or medically attended adverse events