The coronavirus disease of 2019, colloquially known as COVID-19, has been with us for over three years now. Since the discovery of COVID-19 in December 2019, we went through harmful lockdowns in 2020 and various restrictions since then. About 7 million people are in the official COVID death count, although the actual death count very well could be higher. At the same time, there has been progress. We have improved COVID-19 treatment, nothing to say of the creation and dissemination of a vaccine. On top of that, we have greater herd immunity. Researchers at Harvard University estimate that 94 percent of Americans had COVID-19 as of November 2022 (Klaasen et al., 2022). Many countries and jurisdictions have lifted COVID restrictions, which is a welcome move in the right direction.
I remember I wrote a two-part entry almost a year ago on why mask mandates need to go (see here and here). I thought back then that it would be the last time I would ever have to write about masks. I thought we would have moved past it by now because it's 2023, yet here I am writing about masks. Why the argument about masks still matters will be made clear by the end of this piece. But first, I want to cover the evidence on face masks generally and N95 masks specifically.
There is at least intuition to face mask efficiency, which is that covering up the face could mitigate the spread of COVID. There was a strong enough of a mechanistic plausibility argument where I made a libertarian case for a temporary face mask mandate in May 2020, even in spite of the weak evidence base. As I saw the evidence come in, I realized that a) cloth or surgical masks did not have a statistically significant impact, and b) mask mandates did not have additional impact on transmission rates. Let's think why that would be the case:
- COVID particles are small. COVID particles range from 0.15 to 5.0 micrometers. The size of a typical COVID particle is 20 times smaller than a typical bacterium. The small size makes it easier for particles to pass through masks.
- COVID is primarily airborne. Both aerosols and droplets can be generated during sneezing, coughing, talking or exhaling. However, droplets settle quickly, whereas aerosols can potentially travel in air currents for hours. If COVID were primarily transmitted by droplets, masks would have been more effective, but it is primarily airborne.
- COVID is very contagious. On top of being airborne, COVID had a high rate of transmission (e.g., Mahmood et al., 2021). The high reproduction rate and rate of transmission made it easier to infect others and more difficult to contain the virus.
For those who are for masking, they might concede that the cloth masks or the surgical masks are not effective. But what about N95 masks? After all, N95 masks have better filtration efficiency because they can pick up particles more easily. Plus, the N95 fits better over the face, which means less face piece leakage. Intuitively, it would make more sense for an N95 mask to work, or at least work better than a cloth face mask or surgical face mask. Yet the emerging research on the topic has found otherwise.
In December 2022, the Annals of Internal Medicine released a randomized control trial (the gold standard of health research) across 29 health care facilities in Canada, Israel, Pakistan, and Egypt (Loeb et al., 2022). This study compared medical masks versus N95 masks. This study is also significant since healthcare workers are most likely to wear the masks correctly. Even with universal masking policies and tracking potential exposure points, the study showed no real difference. Although it was a randomized control trial, there were nevertheless methodological flaws.
To cover my bases, I bring to your attention this meta-analysis that Cochrane released last week (Jefferson et al., 2023). For context, Cochrane is the gold standard for systematic review of health research, much like the Congressional Budget Office is the gold standard for federal legislative analysis. Cochrane's meta-analysis on physical interventions for respiratory diseases dates back to 2006. It is not some short-term project, but a long-term meta-analysis from one of the foremost health research institutions in the world. The latest 2023 version includes the COVID-specific RCTs. What are the findings from Cochrane?
The pooled results of RCTs did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routing care to reduce respiratory viral infection...Harms associated with physical interventions were under-investigated.
A large group of international researchers looking through dozens of randomized control trials of physical interventions against respiratory diseases. With 276,000 participants in RCTs or cluster RCTs, the researchers at Cochrane cannot even conclude a "modest effect" on infection or illness rates. This finding was not only for cloth masks or surgical masks, but also failing to show that N95 masks work. The pandemic was the best time to collect this sort of data given the high level of mask wearing. If the efficacy of masks were that blatantly obvious, it would have shown up by now in epidemiological data, especially with transmission rates. Yet the most comprehensive research on the topic we have does not show that face masks are effective to fight against COVID-like illness or influenza-like illness.
I can provide two additional explanations as to why N95 masks plausibly do not work. One is that the COVID particles are too small. The second is theory versus practice. If one were to perfectly and consistently wear an N95 mask, it could theoretically work. The problem is the incapability of having oneself masked like that 24/7. It matters much more how they fare in the real world than they do in mechanistic studies taking place in a laboratory. The implausibility of adhering to that rigid standard of mask wearing, whether it is healthcare workers or not, sheds some light onto why the current evidence shows face masks or mask mandates are ineffective.
You might be wondering why this still matters in 2023. This is more than an academic debate looking at past policy. It is not only about how the masking proponents used overblown fear without scientific backing in 2020, equated masking with "love thy neighbor," or how they accused you of being a self-serving libertine or of committing criminal negligence if you did not wear a mask.
Biden's mask mandate was overturned on April 18, 2022. It has been the better part of a year since the overturning and we have seen the number of COVID cases, hospitalizations, and deaths remain relatively low, especially when comparing to previous years.
Yet the Biden administration is still in court trying to appeal. Also, there are also school districts in such states as Pennsylvania, California, and Massachusetts reinstating mask mandates. To quote University of California-San Francisco professor of epidemiology and biostatistics Vinay Prasad and his response to the Cochrane study:
The proponents of masking had a burden. The burden was on their shoulders. You either show it works or you shut up and you take it away. Three years is far too long to continue a practice with no evidence. Not only should it not be mandated, but you do not have evidence to advise the community to do it.
The CDC still recommends masking if you live in a "high transmission" area...in 2023! The government continues to keep us scared with its current recommendations. If "following the science" means "updating one's priors when new evidence becomes available," then the CDC should have already updated their recommendation based on this comprehensive research from Cochrane. But I wager that you will see the same doubling-down and cling to studies with small sample sizes and few controls. Is it really any wonder why I do not trust the CDC with public health advice?
This nation has not healed from the trauma inflicted by the pandemic itself, as well as the fear mongering of the government and the press. Data from market research firm Ipsos shows that as of early December, 60 percent of Americans are wearing masks occasionally. Ten percent wear the masks all the time. It is not only face masks. Research at the National Bureau of Economic Research found that 10 percent will social distance after the pandemic, with an additional 45 percent doing limited social distancing (Barrero et al., 2022).
It was 16 months ago when I wrote that this pandemic would end when we as a society could accept risk again. It is clear that the pandemic and subsequent response to it has left its mark on an entire generation. As much as the United States and other countries have scaled back or removed various COVID restrictions, we are still reeling from the shock of the pandemic. It does not surprise me that we have remnants of COVID restrictions lingering into 2023, but it does dismay me.
I want to end by saying this. If you personally want to wear a mask, that is your right and a matter of your personal autonomy. But no one can seriously lecture me or anyone about "following the science" on face masks when the world's foremost health research organization when it comes to systematic reviews found that face masks do not stop or slow the spread of COVID-19.
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