GENEVA: Maria Van Kerkhove, technical lead on the COVID-19 pandemic at the WHO, said on Friday that airborne transmission of the new coronavirus had always been a concern but that droplets appeared to be the most common infection route.
“Aerosol transmission is one of the modes of transmission that we have been concerned about since the beginning, particularly in healthcare settings … where we know these droplets can be aerosolised – which means can stay in the air longer,” she told an online briefing from Geneva.
The WHO released new guidelines on the transmission of the coronavirus on Thursday that acknowledged some reports of airborne transmission but stopped short of confirming that it spreads through the air, a route that cannot be blocked by the social distancing now common around the world.
Earlier, WHO spokeswoman Dr. Margaret Harris rejected the claim by critics that the agency is biased against the idea of aerosol transmission, saying it recognized the possibility of airborne transmission during medical procedures from early on in the pandemic.
Harris said it is “quite possible” that aerosolization is a factor in some so-called super-spreading events in which one infected person infects many others in close quarters. Many of these events have occurred in places such as nightclubs where people are packed together and are not likely to be careful about protecting themselves or others from infection.
“Most super-spreading events have occurred in indoor places with poor ventilation, with crowding, where it’s very difficult for people to socially distance,” Harris said.
That is why, Harris said, the agency has called for urgent studies to figure out “what really happened in these clusters and what were the big factors.”
