ABSTRACT
Background: This study has assessed the protective effect of a new Anti-COVID-19 SA58 Nasal Spray (SA58 Nasal Spray) against SARS-CoV-2 infection under continuous exposure. Methods: This is an exploratory open-label, single-arm trial. To evaluate the safety and effectiveness of SA58 against SARS-CoV-2 family transmission, SA58 was administered to all enrolled family contacts at 3~6-hour intervals. The frequency of administration and adverse events (AEs) were self-reported by online questionnaire, and RT-PCR tests were used to diagnose SARS-CoV-2 infection. The effectiveness was assessed in comparison to a contemporaneous control group whose information was collected through three follow-up visits. Total effectiveness and single-day effectiveness were calculated. Results: The incidence of SARS-CoV-2 infection was 62.9% (44/70) in the experimental group and 94.8% (343/362) in the control group. Using SA58 nasal spray at least three times per day could possibly reduce the risk of household transmission of SARS-CoV-2 by 46.7%~56.5%. The incidence of AEs was 41.4% and the severity of all AEs was mild. Conclusion: Even under the scenario of continuous exposure to SARS-CoV-2, SA58 nasal spray remained effective in blocking viral transmission and was well tolerated.