Low pH Hypromellose (Taffix) nasal powder spray could reduce SARS-CoV-2 infection rate post mass-gathering event at a highly endemic community: an observational prospective open label user survey.

: Bney Brak city tops Israel's COVID-19 infection rate and mortality. Before the Jewish New Year (two-day gathering) SARS-CoV-2 PCR positivity rates were 17.6% and reached 28.1% two weeks later Taffix - an innovative nasal powder creates a protective gel over the nasal mucosa blocking viruses from infecting nasal cells, was tested for efficacy in preventing SARS CoV2 infection.: In a prospective users survey, 243 members of an ultra-orthodox community that participated in two days prayers were followed for 14 days following this 'superspread' event. Eighty-three used Taffix throughout holiday's prayers and the following two weeks (ITT). Eighty-one used it regularly (PP). Two used it rarely if at all. The remaining 160 did not use Taffix.: After 14 days, 0/81 (0%) of (PP) Tafffix users, 2/83 (2.4%) of (ITT) Taffix users and 16/160 (10%) nonusers were infected. Odds ratio for infection among Taffix users was 0.22, a reduction of 78% (95%CI 1%-95%). No side effects reported.: Taffix could be an additional tool against COVID19 spread, in addition to recommended safety measures. This is the first time that a prevention measure of SARS-CoV-2, beyond the use of masks, has proved effective.