Randomization and masking
After enrollment, participants were randomized in a ratio of 3:1 to receive SA58 or placebo at the study site. A statistician (independent of the study) assigned treatment at random using a standard computer pseudorandom number generator. Given that our study was conducted in a COVID-19 outbreak setting, only the participant was blinded and unaware of what had been allocated. The sponsor/investigators were unblinded for treatment to meet the sites’ requirements of taking high standard of efforts to secure the safety of participants without any delay.