COVID-19 Prevention Trial: Effect of Prophylactic Use of TAFFIX™ on Infection Rate by SARS-CoV-2 Virus (COVID-19).

Study Design: This is a 2 arms, Randomized, double blind, placebo controlled clinical trial. Study population: Subjects who, were not diagnosed with COVID-19 previously to their best knowledge and according to COVID-19 antibody test. Were not vaccinated yet against COVID-19 and will not be vaccinated during their participating in the study. Up to 1000(500 per study arm) will be enrolled for the purpose of this study. Study treatment: TaffiX™ will be used daily (up to 3 times a day, every 5 hours) in addition to the protective measures instructed by the Ministry of Health The control group will be administrated with Placebo- lactose powder for nasal application Participation duration: Up to 6 weeks Concomitant therpay: Allowed- no restriction for Concomitant Medications Planned interim analyses: When no less than 150 subjects have completed the study, an interim analysis for Efficacy and safety will be conducted by an independent biostatistician. After no less than 500 subjects, additional interim analysis for Efficacy and safety will be conducted by an independent biostatistician. Serious adverse events will be monitored by an independent safety officer on an ongoing basis throughout the study. Stop Rule: If the proportion of COVID-19 positive rate in the treatment group is statistically significantly lower than the proportion of COVID-19 positive rate in the placebo control group.