W.H.O. to Review Evidence of Airborne Transmission of Coronavirus

After hundreds of experts urged the World Health Organization to review mounting scientific research, the agency acknowledged on Tuesday that airborne transmission of the coronavirus may be a threat in indoor spaces.

W.H.O. expert committees are going over evidence on transmission of the virus and plan to release updated recommendations in a few days, agency scientists said in a news briefing.

The possibility of airborne transmission, especially in “crowded, closed, poorly ventilated settings, cannot be ruled out,” said Dr. Benedetta Allegranzi, who leads the W.H.O.’s committee on infection prevention and control.

She said the agency recommends “appropriate and optimal ventilation” of indoor environments, as well as physical distancing.