It was apparent very early that there were spread patterns only explainable by aerosols. The Diamond Princess was the earliest publicized example, with cases occurring onboard despite isolation in cabins. Japanese experts understood the lesson immediately and implemented a "three C's" approach to counter airborne spread: avoid close contact, closed spaces, and crowds.
Western governments and experts and the WHO instead took a "lalalala I can't see this" and to this day many still deny airborne transmission and advocate droplet and fomite precautions.
There was not in fact any great mystery about aerosol spread unless you were positively convinced it was impossible. The early tech fact checking was based on this denial, rather than a good faith uncertainty.
While it took way way way too long for the scientific community to recognize airborne spread, it's hard to say that stuff like Diamond Princess could ONLY be explained by airborne spread. It was early in the pandemic, the disease was poorly understood. It's hard to know if the quarantine was effective--passengers could have continued socializing, sick workers distributing food may have been spreading it, etc.
It's a big leap from a single data point.
The more damning issue is that the assumption that it wasn't airborne in the first place wasn't really well founded.
> While it took way way way too long for the scientific community to recognize airborne spread
I would make that more specifically as referring to the Western public health establishment, especially the CDC and WHO. Actual scientists were comfortable saying recognition was overdue fairly early on, reaching the point in July 2020 where a large group published an open letter:
Ok, best explained. If you had no prior bias, airborne spread was most likely cause for Diamond Princess pattern. Western society and WHO had a 100 year prior bias against accepting that respiratory diseases spread via the air.
It all comes back to the victory of germ theory over miasma theory. Germ theory is accurate but people got overzealous. Not all germs need be fomites.
Just to be clear, I am not in any way defending the CDC’s botching the understanding that COVID’s primary means of spreading is airborne. I just remember reading about this on social media, including Zeynep’s many posts, without ever seeing those moderated. Given the general tenor of this post, I suspect that the author might have been lumping reasonable claims many experts supported in with more speculative claims.
The screw-up the title refers to is that the medical definition of the droplet/aerosol threshold has been wrong for most of a century, and the source only just tracked down in late 2020/early 2021.
Also buried in there is an interesting tidbit that experts resist aerosol spread in general because it's too similar to the long-discredited miasma theory, so each virus has had to individually be proven in a lab to have aerosol spread before it's acceptable to say so.
This is true but a more subtle distinction about size of droplet.
If the virus spread primarily by aerosols then cloth and surgical masks would have little preventative value. But we know that they do have preventative value.
The reality as understood today is a mix of droplet sizes. Larger droplets carry more load and hence more risk but work over a smaller radius. But smaller droplets can carry enough load to infect; especially since later variants seem more infectious (i.e. require a smaller load to gain a foothold).
Not so. Surgical masks still filter about 50-60% of aerosols. They are made of similar material to N95 masks, only issue is fit.
A 50-60% reduction has substantial effects! There's been a lot of "perfect is the enemy of the good, and the good is useless" in this pandemic, but we know that 100% of people do not get instantly infected when exposed, so dropping levels by half will have a substantial impact, especially if the infected source wears such a mask too
Western governments and experts and the WHO instead took a "lalalala I can't see this" and to this day many still deny airborne transmission and advocate droplet and fomite precautions.
There was not in fact any great mystery about aerosol spread unless you were positively convinced it was impossible. The early tech fact checking was based on this denial, rather than a good faith uncertainty.
Zeynep Tufecki wrote a good article about how airborne spread was resisted: https://www.nytimes.com/2021/05/07/opinion/coronavirus-airbo...