Incidence of virologically-confirmed COVID-19 <br/ >disease starting 14 days after completion of the <br/ >2-dose regimen until 12 months post-dose 2 (End <br/ >of Study (EOS)) in subjects who are SARS-CoV-2 <br/ >seronegative at baseline.Timepoint: Day0;week4;week6;week18;week30; week42;week56

Incidence of virologically-confirmed COVID-19 <br/ >disease starting 14 days after completion of the <br/ >2-dose regimen until 12 months post-dose 2 (End <br/ >of Study (EOS)) in subjects who are SARS-CoV-2 <br/ >seronegative at baseline.Timepoint: Day0;week4;week6;week18;week30; week42;week56