Efficacy of NONS in the prevention of COVID-19 infection as determined by a positive COVID-19 test (antigen or reverse-transcriptase polymerase chain reaction [RT-PCR]). [Between Day 1 to Day 28]

Efficacy of NONS in the prevention of COVID-19 infection as determined by a positive COVID-19 test (antigen or reverse-transcriptase polymerase chain reaction [RT-PCR]). [Between Day 1 to Day 28]