Benedetta Allegranzi, a WHO official, said that given the speed at which Covid-19 is spreading and the joint statement made by a group of 239 scientists in the Oxford science journal, Clinical Infectious Diseases, pointing to evidence that the airway was a more than likely source of infection, they have finally accepted that this is a real possibility.

The WHO has already been criticized for taking too long to accept that the masks were a powerful tool to stop the spread of the coronavirus, which already has more than half a million victims around the world.

WHO experts have pointed out that “there is new but uncertain evidence about possible airborne transmission routes, this possibility is especially under very special conditions, such as crowded and poorly ventilated places”.

So far, the team of scientists and the World Health Organization have agreed that the virus is transmitted through saliva particles expelled when a person speaks, coughs or exhales. However, they have different effects on these particles in enclosed spaces. To date, the World Health Organization has said that the particles can spread up to two meters and then fall to the ground. Instead, these researchers say they have evidence that the virus can spread several meters indoors, especially viruses with poor ventilation, increasing the risk of infection.

Van Kokhov, technical director of WHO’s Office of Emergency Health, said: “We recognize that new evidence is emerging in this area, and we add that you need to be open to this evidence and understand its impact on the mode of transmission and preventive measures taken.