It seems that way. Here's another analysis of studies that focused on indoor humidity.

>"If the relative humidity of indoor air is below 40 percent, the particles emitted by infected people absorb less water, remain lighter, fly further through the room and are more likely to be inhaled by healthy people. In addition, dry air also makes the mucous membranes in our noses dry and more permeable to viruses," summarizes Dr. Ajit Ahlawat.

https://www.tropos.de/en/current-issues/press-releases/detai...

Actual paper:

https://aaqr.org/articles/aaqr-20-06-covid-0302

Thailand and Vietnam also had 95% compliance with mask wearing.

https://www.worldpoliticsreview.com/articles/28979/what-s-be...

Interesting how these countries where infections are trending the right way are so compliant. And then when infections are trending the other way, suddenly they are no longer compliant any more.

Like Japan, oh the population is so used to wearing masks so everything is going great. Except when cases went up, that was when they suddenly had a memory lapse and forgot how to wear their masks.

And so does the US:

https://www.webmd.com/lung/news/20201022/mask-use-by-america...

https://www.pewresearch.org/fact-tank/2020/08/27/more-americ...

Break it down by county or state, and you'll find that many of the the areas with the highest reported compliance have the worst overall metrics:

https://delphi.cmu.edu/covidcast/?date=20210209&region=42003...

(and before anyone says it: sure, you can argue that mask-wearing correlates with population density or some other factor that leads to greater disease prevalence, but doesn't that just beg the original question? People are wearing masks the most in the places with the highest disease prevalence. If "the reason" that Vietnam did well is mask compliance...well, why didn't it work just as well here?)

SNIP

" Our review of the literature offers evidence in favor of widespread mask use as source control to reduce community transmission: Nonmedical masks use materials that obstruct particles of the necessary size; people are most infectious in the initial period postinfection, where it is common to have few or no symptoms (45, 46, 141); nonmedical masks have been effective in reducing transmission of respiratory viruses; and places and time periods where mask usage is required or widespread have shown substantially lower community transmission.

The available evidence suggests that near-universal adoption of nonmedical masks when out in public, in combination with complementary public health measures, could successfully reduce Re

to below 1, thereby reducing community spread if such measures are sustained. Economic analysis suggests that mask wearing mandates could add 1 trillion dollars to the US GDP (32, 34).

Models suggest that public mask wearing is most effective at reducing spread of the virus when compliance is high (39). "

FROM

An evidence review of face masks against COVID-19 by Jeremy Howard, Austin Huang, et al.

https://www.pnas.org/content/118/4/e2014564118

Yeah, I've read it, and I've read everything cited in it. In the evidentiary contest between a review paper and empirical reality...reality wins. But let's put a pin in that for a second. This is a bad review, and people need to know why.

This review completely misrepresents the results of cited papers, and is extremely sloppy with many others. For example, they claim that this RCT [0] found evidence supporting mask use for influenza, when in reality, it found no significant difference versus the control. Yet the authors of the Howard review blatantly mis-represent the top-line conclusion of the trial:

> There has been one controlled trial of mask use for influenza control in the general community....It found that “in an adjusted analysis of compliant subjects, masks as a group had protective efficacy in excess of 80% against clinical influenza-like illness.”

Moreover, this review omits the only randomized controlled trial ever conducted for masks and Covid [1] (which found no statistically significant protective effect), presumably because the RCT didn't support their argument.

In general, this review's sloppy use of citations (as in the section you've quoted) mixes statements of facts with dubious assertions -- unsupported by any evidence at all -- in order to make it seem that those assertions are fact. For example, from your quote, it's trivial to see examples:

> "nonmedical masks use materials that obstruct particles of the necessary size"

I don't know what "nonmedical masks" are, but the category is so broad that a statement like this is utterly meaningless, even if it were backed by a citation (which it isn't).

> "nonmedical masks have been effective in reducing transmission of respiratory viruses"

Again, I'm not sure what a "nonmedical mask" is, but there's no citation here, so this is just a bald assertion.

The evidence base for masks -- of any sort -- against respiratory viruses is so weak that even recent a review published by the CDC in May 2020 argues that they have no effect [2]. For cloth masks specifically, the only randomized trial ever conducted showed that people wearing cloth masks were worse off than those wearing surgical masks [3].

There have been a number of fair, quality reviews of the mask debate (for example, [4]). This is not one of them.

[0] https://www.researchgate.net/profile/Esam_Azhar2/publication...

[1] https://www.acpjournals.org/doi/10.7326/M20-6817

[2] https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4420971/pdf/bmj...

[4] https://www.cebm.net/covid-19/masking-lack-of-evidence-with-...

>And so does the US:

This is not my actual experience in the United States. It's practically impossible to find a laundromat in Rhode Island that isn't constantly full of maskless noses, and we're a blue state.

EDIT:

>More than nine in 10 U.S. adults (93%) said they sometimes, often or always wear a mask or face covering when they leave their home and are unable to socially distance, including more than seven in 10 (72%) who said they always do so, the poll revealed.

That's not 93% compliance, it's 72% compliance. In other words, the noncompliance rate is five times higher!

Both your links claim less than 95% compliance, and both suggest a recent, marked improvement in mask wearing from earlier dates (but still well after the start of the pandemic).

The last link (with the most recent data) shows well over 95% compliance in urban areas. The first link is over 90% nationwide. Surveys, no matter where they happen, have margins of error.

But regardless, are you seriously arguing that the difference between Vietnam and the US is...a few percent difference in self-reported mask compliance?

If the miracle cure of masking requires 100% compliance amongst 330 million people, your plan is doomed from the start.

How would those same places be doing without masks?

India doesn't, and for the life of me can't figure out where the disease disappeared. There are cases and even if the govt is suppressing numbers it's still outrageously nonexistent given the level of normalcy everything has gone to.

Yeah Brazil and specifically Manaus in the middle of the Amazon rainforest is doing a great job.

Considering that Brazilian scientists described the government's strategy as an "institutional strategy to spread the coronavirus"[1] and they're reporting a lower death rate than France[2], you have to figure something in Brazil is working in humanity's favor. It can't make up for (probably) the worst policies in the world, of course.

[1]: https://english.elpais.com/americas/2021-01-29/study-finds-t...

[2]: https://www.worldometers.info/coronavirus/

A bit more than 20% of the people in France are over 65.

For Brazil, it's a bit more than 9%.

We know very well that age is a significant factor.

I've seen some estimates that with the same age distribution as Brazil France would have had half the number of deaths: https://www.bbc.com/portuguese/brasil-55847831 (Portuguese link)

It may be a factor, but it's a pretty big leap to say that's what is behind countries' successes and failures. I mean, I've even seen people claiming it's due to "Asians eating a lot of fish".

The most obvious explanation is (even literally) right in front of our noses: politics, culture and age distribution.

Your hypothesis does not square with the unfolding tragedy.

https://www.doctorswithoutborders.org/what-we-do/news-storie...

I don't think you can conclude anything from those numbers. On the one hand Brazil is very likely underreporting and has a much younger population, but on the other hand their medical care is not as good.

Sarcasm?

https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

( Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence )

Yes, pure sarcasm. Quite a catastrophe there. And a cautionary tale for what happens when denialists get their way.

A recent paper showed that obesity was related to spreading sars-cov-2 more readily, not just the severity of disease of the obese individual. The US and UK are world leaders in both obesity and virus spread. And the countries doing well with the virus are healthy and well within the normal weight range. I don’t honestly believe it will be as simple as this, but it’s amusing to think this _could_ be the big surprise connection.

https://www.pnas.org/content/118/8/e2021830118?fbclid=IwAR3q...

Related, when it comes to youth sports as vectors for coronavirus transmission, ice hockey is a clear outlier, and the low humidity levels in ice rinks is a primary theorized reason: https://www.washingtonpost.com/health/2020/12/04/hockey-covi...

Places like the US have wildly varying levels of humidity, seems like a good place to study that

You'd have to separate out the effect of AC though. In the hottest and wettest parts of the country, people may actually live more of their lives in cold and dry air-conditioned environments than in the north...

Oof, that's a good point. And lots of people in the inland west (we're it's extremely dry) have whole home humidifiers...