Thursday, August 12, 2021

We Do Not Need Mask Mandates to Fight the Delta Variant

We were making such progress with the pandemic in the United States. We got through the COVID peak in the winter. Since the vaccine rollout began in December, 71.3 percent of adults have received at least one dose as of August 11. Restrictions were getting lifted across the country. It looked like we were seeing the end of the tunnel with this pandemic. Then the Delta variant, a strain of COVID that is about twice as contagious as the Alpha variant (i.e., R0≈7), came along. In response to this variant, multiple cities have reinstated mask mandates, including Los Angeles, Phoenix, and Washington, D.C. 

There has been a partisan divide throughout this pandemic. Generally speaking, Democrats have taken the pandemic more seriously and have been more scared of coronavirus. Republicans, on the other hand, have not taken it as serious and are less afraid. Independents are somewhere in between. This trend has borne out by survey data. Republicans show a lower rate of vaccinations than other demographics (Kaiser Family Foundation). This divide is not confined to the vaccines. To quote Reason Magazine contributor Robby Soave, "In practice, people who don't want to get the vaccine are unlikely to follow the other, more annoying mitigation strategies. On the contrary, the places that are most likely to reintroduce the mask mandates and see widespread compliance are places where vaccination rates are high." According to a Morning Consult survey from August 4, both the unvaccinated and Republicans are less likely to wear masks going forward than the vaccinated and/or Democrats. Although the pandemic has been greatly politicized, we should not view it in those terms. The question is whether these mandates are going to help or if it is an exercise in futility. 

Before the Delta variant arrived, the question about mask efficacy has been in question. In the medical journal JAMA, they wrote in March 2020 that "face masks should not be worn by healthy individuals to protect themselves from acquiring respiratory infection because there is no evidence to suggest that face masks worn by healthy individuals are effective in preventing people from becoming ill (Desai and Mehrotra, 2020)." I looked at the question of face mask effectiveness twice last year (see here and here). At that time, I found inconsistent evidence, but was also mildly supportive of a temporary, indoor face mask mandate because a) they work under certain conditions (e.g., high compliance rate, more effective indoors and in larger crowds), b) they come with a lower cost (especially compared to lockdowns), c) surgical and N95 masks work much better than cloth masks, and d) there was an overriding public health concern. Looking at World Health Organization recommendations, I concluded that, at best, face masks would be but part of a more comprehensive strategy since their efficacy was lower than such a measure as social distancing. In December 2020, the WHO stated in its interim mask guidance (p. 8) that "there is only limited and inconsistent scientific evidence to support the effectiveness of masking healthy people."  That was the prominent WHO about a year into the pandemic, and that was the best they could say about masking healthy people. The American Institute for Economic Research released a piece on mask efficacy evidence that I found to be a good read. Needless to say, how I view the masks are that their efficiency is modest at best, and inconsistent and negligible at worst. 

In addition to asking whether the masks are effective, there is also a question about whether the mandates work. Lockdowns provide a good example and proxy of voluntary versus mandated behavior. Lockdowns were advocated for not based on evidence (because none existed at the time), but on modeling. The modeling made generous assumptions about the benefits of lockdowns while giving most, if not all, the credit, to lockdowns. The evidence is coming in with regards to lockdowns, and what we have been seeing is that lockdowns are ineffective. There are multiple reasons, but one of the big reasons was that people were social distancing without the lockdowns. People did not need a mandate. By and large, they voluntarily kept their distance. Do we see a similar phenomenon with masks? Were most people already masking before the mandates? Would people have worn masks regardless of the mandates? A recent study from the International Monetary Fund fails to make the distinction, which is why I ask these questions (Hansen and Mano, 2021). Were the mask mandates a primary cause in saving lives or were they simply incidental and correlational? 

We can look at multiple countries that implemented mask mandates and the number of cases still surged, especially last winter. I could also point out that Sweden has not had a mask mandate and its current COVID problem is all but nonexistent. I can show some earlier analysis from the Heritage Foundation, but I want to show a recent ecological study from the University of Louisville (Guerra and Guerra, 2021). The researchers found that although 80 percent of states mandated masks, the mandates "did not predict lower growth rates when community spread was low [minima] or high [maxima]." The conclusion thus inferred was that the mandates were unlikely to have affected COVID-19 case growth.


What makes all this discussion about how they have fared thus far is a case of "that was then, this is now." Two major changes have taken place in recent months. These changes do not make the previous discussion about masks pointless, but it does change the context. One such change is that the prominent strain of COVID [in the United States], the Delta variant, is significantly more contagious. You could make an argument that masks could be more effective against Delta. It is soon to tell since we do not have data to back up the assertion. The closest we have is previous research and inferences we can make. On the other hand, as I would argue, the rate of transmission is high enough that even if you go with the generous assumption of masks reducing transmission from 30 to 50 percent, there will still be high transmission in absolute terms. The second change is that the vaccination campaign is well under way. I discussed vaccine mandates a couple of weeks ago, and you can read an elaboration of the aforementioned changes here. What I will say is that while the idea of a more contagious disease sounds scary, it is not as simple or as catastrophic as "cases are surging" sounds.

Sir Andrew Pollard, who heads the Oxford Vaccine Group, said that while vaccinations slow the spread, they do not eliminate transmission. However, the odds of catching it as a vaccinated individual (i.e., a breakthrough case) is low. As the Kaiser Family Foundation points out in its research of state-level data earlier this month, the odds of a breakthrough case are less than one percent. More to the point, hospitalizations and deaths are really low for the vaccinated. Pollard also said that even if the vaccine-induced antibodies waned, odds are that our immune systems would remember enough to offer a degree of protection for decades. So why does transmission matter if actual harm has decreased? As infectious diseases expert Professor Paul Hunter brings up, we shouldn't frighten ourselves with high [confirmed case] numbers that do not translate into disease burden. 

Hospitalizations and deaths are much better indicators of disease burden than cases. What have we seen since the vaccines have taken hold? In most jurisdictions, there has not been a corresponding, comparable rise in hospitalizations and deaths. The areas getting heavily hit are those with low vaccination rates (although, to be fair, the places in the Southern U.S. are also dealing with hotter summer weather, which means they are indoors more often than the rest of the year). Looking at the American Hospital Associations Bed Occupancy Projection Tool, most parts of the U.S. are not above 70 percent. For context, the CDC calculated in 2015 that average bed occupancy was 65.5 percent. You can go through the data on hospitalizations and deaths yourself. When you do look at the numbers, I hope you see what I see, which is that the disease burden is not there to justify the mask mandates.

To summarize, our focus should not be on renewed mask mandates. Why? For one, mask mandates, as opposed to general mask-wearing, are shown to have been negligible at best. It has hardly been the silver bullet that proponents make it out to be. Two, the unvaccinated are less likely to wear masks than the vaccinated. Three, those who have been pushing for the mask mandates are the ones most likely to assume that we can get rid of COVID. Historically, we have only eradicated smallpox and rinderpest. A mask mandate distracts us from being able to accept that COVID is most likely to be endemic, i.e., it's not going anywhere. If endemicity is the future, then at best, masks would only delay the inevitable. Finally, one of the most prevailing features of those entering the hospitals for COVID are that they are not vaccinated. Fauci was right that this pandemic has become a pandemic of the unvaccinated. That being the case, mask mandates make little sense if the unvaccinated are the drivers of COVID at this stage. Vaccines are safe and effective. They have been shown to be especially effective against severe COVID cases and COVID deaths. Instead of spurious mask mandates or the CDC using mixed messaging about vaccines and face masks, what needs to happen is a solid vaccine campaign with unambiguous messaging so we can get our lives to as close to "pre-pandemic normal" as possible. 

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