Blue photobiomodulation LED therapy impacts SARS‐CoV‐2 by limiting its replication in Vero cells

Zupin, Luisa; Gratton, Rossella; Fontana, Francesco; Clemente, Libera; Pascolo, Lorella; Ruscio, Maurizio; Crovella, Sergio

The study of any intervention able to counteract SARS‐CoV‐2 pandemic is considerably envisaged. It was previously shown, in in vitro models of infections, that the LED blue light is able to decrease the viral load of HSV‐1 and ZIKV. In our study, LED photobiomodulation therapy (PBMT) at blue wavelengths (450, 454 and 470 nm) was tested in an in vitro model of SARS‐CoV‐2 infection, employing three experimental settings: SARS‐CoV‐2 was irradiated and then transferred to cells; already infected cells were irradiated; cells were irradiated prior to infection. A decrement of the viral load was observed when previously infected cells were irradiated with all three tested wavelengths and relevant effects were registered especially at 48 hours post‐infection, possibly suggesting that the blue light could interfere with the intracellular viral replication machinery. Our in vitro findings could represent the starting point for translational applications of PBMT as a supportive approach to fight SARS‐CoV‐2. [Image: see text]