[BostonCard]

https://www.nytimes.com/2020/07/04/healt...borne.html

A bunch of experts write the WHO asking it to evaluate the evidence for airborne spread. "The World Health Organization has long held that the coronavirus is spread primarily by large respiratory droplets that, once expelled by infected people in coughs and sneezes, fall quickly to the floor."  That is probably true, but the word "primarily" is doing a lot of work there, and if you read more closely, the WHO has stated "airborne transmission of the virus is possible only after medical procedures that produce aerosols".  So, if a substantial proportion of cases are spread via airborne route, rather than droplets, that has very large implications.  For example, mask wearing is predicated on stopping droplets from being expelled, but it is not helpful for reducing spread of airborne particles.

But in an open letter to the W.H.O., 239 scientists in 32 countries have outlined the evidence showing that smaller particles can infect people, and are calling for the agency to revise its recommendations. The researchers plan to publish their letter in a scientific journal next week.

In my mind, the question is how much of a substantial minority of cases were due to airborne particles?  Is it like 1/3, in which case there are major repercussions.  On the other hand, if it is <5% then this is something to be aware of, but you tailor your health measures to the low hanging fruit, which is reducing droplet spread.

BC

[BostonCard]

https://www.nytimes.com/2020/07/04/healt...borne.html

A bunch of experts write the WHO asking it to evaluate the evidence for airborne spread. "The World Health Organization has long held that the coronavirus is spread primarily by large respiratory droplets that, once expelled by infected people in coughs and sneezes, fall quickly to the floor."  That is probably true, but the word "primarily" is doing a lot of work there, and if you read more closely, the WHO has stated "airborne transmission of the virus is possible only after medical procedures that produce aerosols".  So, if a substantial proportion of cases are spread via airborne route, rather than droplets, that has very large implications.  For example, mask wearing is predicated on stopping droplets from being expelled, but it is not helpful for reducing spread of airborne particles.

But in an open letter to the W.H.O., 239 scientists in 32 countries have outlined the evidence showing that smaller particles can infect people, and are calling for the agency to revise its recommendations. The researchers plan to publish their letter in a scientific journal next week.

In my mind, the question is how much of a substantial minority of cases were due to airborne particles?  Is it like 1/3, in which case there are major repercussions.  On the other hand, if it is <5% then this is something to be aware of, but you tailor your health measures to the low hanging fruit, which is reducing droplet spread.

BC