https://vinayprasadmdmph.substack.com/p/do-masks-reduce-risk...
We really need to stop repeating the talking point that "everyone screwed up". The original evidence base was that masks don't do much to stop respiratory illness. "The science" changed in the span of a week in early 2020, based on little more than propaganda. No actual science was ever performed, and once we did some, we found out that the early evidence was pretty much correct.
Each random person's picture of masks will be very different from what the next person is thinking.
And it's also very important to distinguish between the different meanings of viral transmission – of what virus, and according to what scientific results it's being talked about.
A lot of the friction comes from this.
In SARS-CoV-2 transmission specifically, I speak about it as airborne or aerosolized, based on all the papers that are out that confirm that now, and I when I say "masks" I tend to think of gaping surgical masks or better, and no, those don't work well enough.
However in the sense of the word masks as N95/FFP2 masks or better—often called respirators—then those masks are almost unreasonably effective at stopping transmission.
Here's the data I base my perspective on, in the nutshell form of some tweets from scientists, tweets linking to scientific papers. (Some are peer-reviewed, some at the preprint stage.)
https://twitter.com/JenniferKShea/status/1449748053548752903 — We've summarized the literature supporting airborne transmission of COVID-19 & several other respiratory pathogens. Guess what? #COVIDisAirborne
https://twitter.com/mjb302/status/1409628852867850240 — Important new research examining the real world impact better PPE has on workplace acquired infections of SARS-CoV2. — TL:DR - FFP3 respirators provide 100% protection to healthcare workers looking after patients infected with SARS-CoV2. 1/25
https://twitter.com/andymoz78/status/1441355141051936772 — A thread on our recent pre-print “The removal of airborne SARS-CoV-2 and other microbial bioaerosols by air filtration on COVID-19 surge units” (*Pre-print -not peer reviewed*) — TL:DR Hospital air is dirty, we can clean it
https://twitter.com/DFisman/status/1454776521818886145 — Remarkable new work from Korea shows the extraordinary impact of masks on SARS-2 transmission on public transit. — Parameterized based on *aerosol* simulator. (Because SARS-2 is airborne). Distancing helps, but less important (b/c SARS-2 = airborne).
https://twitter.com/caruzycki/status/1360635674324463616 — 2/ If this disease were only spread by droplets that fell to the ground within 2 metres, [plexiglass barriers] would be a perfectly fine solution to limit transmission. Unfortunately, we unequivocally know that aerosols are important with this disease.
If you have any issues with my comment above which is based on clearly delineated and reasonable personal opinion and includes links to the scientific results it is based on, you have a duty to respond, not downvote.
People keep dismissing this, but respirators in hospitals are very different than respirators in the hands of the general public. Fit matters more than anything else, and hospitals have staff and procedures to ensure that PPE is used correctly.
This isn't a small or theoretical concern. Even a tiny gap negates the effect of the respirator, and people don't fit their respirators properly -- in large part because properly worn respirators are annoying and hard to tolerate for long periods of time. I regularly see people walking around with KN95 masks on their faces, with massive gaps around the nose and chin. These masks are pure viral theater.
(Also, not for nothing: two of the twitter links you cite are about respirators in hospitals. the other two are mechanistic studies, which are basically useless. Every failed intervention or drug in the history of medicine has a mountain of plausible mechanistic studies supporting it. Most things don't work, but everything we try has someone claiming that it's a sure-fire solution, based on a lab study.)
In hospitals, high importance is rightfully placed on correctly fitting N95/FFP2 and up – this is so that they function to spec and can be formally assumed to work like the specification indicates so they can be applied as a tool in general use by, well, by a population of staff.
This does not mean that respirators which are worn in a reasonable manner will ever be as poor filtration devices as gaping masks, especially not if the pathogen is airborne / aerosolized and operates almost purely as air flow, not droplets with mass and inertia to consider.
And COVID-19 is airborne and must be considered as airborne. There were five links, and the fifth is a collection of papers :) There is also a significant amount of detail and discussion and framing and context in adjacent tweets i all the links.
Dr. Tam, who is responsible for both gross incompetence AND intentionally misleading the public WRT COVID19, mistakes that literally killed people and, is probably still killing people, remains in her position as Chief Public Health Officer of Canada. This is why I can't let it go.
On a serious note, how often did they really mess up? In a sense of having consequences that are close to impossible to fix? Not once, if you ask me.
Not all lies are malicious. Some are necessary. "Masks aren't helpful" was one of those. Everyone with a three-digit IQ should have understood what was really going on, and everyone else was better off believing the lie.