Hypothiocyanite and hypothiocyanite/lactoferrin mixture exhibit virucidal activity in vitro against SARS-CoV-2

SARS-CoV-2 replicates efficiently in the upper airways during the prodromal stage, re-sulting in environmental viral shedding from patients with active COVID-19 as well as from asymp-tomatic individuals. There is a need to find pharmacological interventions to mitigate the spread of COVID-19. Hypothiocyanite and lactoferrin are molecules of the innate immune system with a large spectrum cidal activity. The Food and Drug Administration and the European Medicines Agency designated the hypothiocyanite and lactoferrin combination as an orphan drug. We report an in vitro study showing that micromolar concentrations of hypothiocyanite exhibit dose-and time-de-pendent virucidal activity against SARS-CoV-2 and that the latter is slightly enhanced by the sim-ultaneous presence of lactoferrin.