What about humidity of the environment? Is that a reason behind the success of countries like Thailand, Vietnam in tackling Covid?
Possibly relevant study: https://www.annualreviews.org/doi/10.1146/annurev-virology-0...
Possibly relevant study: https://www.annualreviews.org/doi/10.1146/annurev-virology-0...
>"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://www.worldpoliticsreview.com/articles/28979/what-s-be...
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.
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®ion=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?)
" 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.
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-...
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!
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.
[1]: https://english.elpais.com/americas/2021-01-29/study-finds-t...
For Brazil, it's a bit more than 9%.
We know very well that age is a significant factor.
The most obvious explanation is (even literally) right in front of our noses: politics, culture and age distribution.
https://www.doctorswithoutborders.org/what-we-do/news-storie...
https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
( Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence )
https://www.pnas.org/content/118/8/e2021830118?fbclid=IwAR3q...