239 Scientists to WHO: Come On. Coronavirus Is Airborne

The WHO still won't call the coronavirus airborne, even though evidence increasingly shows it is indeed transmissible that way and experts have been warning for months that more attention needs to be paid to transmission via aerosols. Now, 239 scientists from more than 30 countries have published an open letter to the health agency urging it to reconsider its official stance on the matter, which currently states only that the research is inconclusive. "There is no incontrovertible proof that SARS-CoV-2 travels or is transmitted significantly by aerosols, but there is absolutely no evidence that it’s not," one doctor tells the New York Times. "So at the moment we have to make a decision in the face of uncertainty, and my goodness, it’s going to be a disastrous decision if we get it wrong. So why not just mask up for a few weeks, just in case?"

The WHO's official stance is that the virus that causes COVID-19 is transmitted via larger respiratory droplets, which typically can only travel about 6 feet before they fall to the ground. Aerosols, on the other hand, are smaller particles that can travel much longer distances and linger in the air, meaning that if the virus is transmitted that way, crowded indoor spaces, especially those with poor ventilation, are a big risk even when social distancing can be maintained. That means more measures (from masks to upgraded air filters and UV lights) may be necessary for true protection. "WHO’s credibility is being undermined through a steady drip-drip of confusing messages, including asymptomatic spread, the use of masks, and now airborne transmission," one expert tells the Washington Post. The Times has much more, including how a "dated" definition of airborne transmission might be contributing and why it's difficult to study aerosols. (More coronavirus stories.)