What is the consensus in the scientific community over COVID-19's mode of transmission?

Question

I've read from many news and scientific sources that COVID spreads primarily through respiratory droplets, but I've also read multiple sources that have said we don't entirely know yet. Is it fomites, droplets, or aerosols? Is it some combination? Do we have a complete understanding of it?

With how infectious the B117 variant appears to be, it seems like it would spread through aerosols, since most other infectious diseases that are very contagious tend to spread through aerosols, like measles, tuberculosis and varicella. If that's the case, why do so many sources keep claiming that it's through droplets? I've also read an article on the Johns Hopkins website that suggested the scientific community was initially wrong about the mode of transmission for tuberculosis, so is that possible for COVID?

Thank you!

Answer 1

The terminology really depends on the scientific field. You also have to be aware that sometimes terminology is simplified for the purposes of presenting information to the general public.

A droplet can really mean anything from a few micrometers up to several millimeters and it does not necessarily have to be spherical. The key point is that the virus may spread through droplets.

Aerosols typically refer to small solid particles or liquid droplets, maybe less than 20 micrometer in size, but again, it depends on the field.

In quiescent air, any heavy (more dense than air) particulates (solid or liquid) which are about 1 micrometer or less will remain suspended in the air for several hours due to Brownian motion and also the fact that their gravitational settling velocity is small.