The politics of masking and why masks are not just for Covid-19

CLINICAL MATTERS

When we play politics with health, people die. Nowhere has this been truer than during this pandemic. In this era of rampant misinformation, the evolving nature of science has been weaponized to cast doubt on the most basic of public health interventions. Among the victims of this disinformation are two major pillars of the pandemic response—Covid-19 vaccines and masks. Both interventions have been irrationally attacked despite strong evidence that they work and have already saved millions of lives.

Covid-19 vaccines are estimated to have prevented over 20 million deaths in the first year of use alone. This doesn’t even take into account its effect on the reduction of infection, severe disease, and long Covid-19. While there have been some early safety concerns, subsequent studies have shown that rare side effects from the vaccines are far outweighed by the benefit of taking them.

For instance, the risk of myocarditis from getting a Covid-19 infection is many times higher than from an mRNA vaccine. Vaccine safety and the potential of new bivalent vaccines to restore some protection against the new variants of concern was recently discussed in a previous column (https://mb.com.ph/2022/10/18/the-shot-that-saves-lives/). Despite the clear scientific benefits of vaccines, a significant number of people remain unvaccinated and/or unboosted due to fear-mongering and fake news. The sustained low number of Covid-19 hospitalizations despite more transmissible variants is prima facie evidence that vaccines continue to work, especially in the prevention of severe Covid-19.

While there has always been strong evidence supporting the utility of vaccines, this was less certain early on for masks. At the start of the pandemic, the World Health Organization (WHO) did not recommend masks for people who were not symptomatic. There were several reasons for this recommendation.

The first reason is that it was thought that Covid-19, like SARS, was not significantly transmitted by asymptomatic carriers. Therefore, only those with colds, fever, and other symptoms had to wear masks. The second reason is that there was an acute shortage of personal protective equipment (PPE) for healthcare workers, including masks. Third is that while surgical masks were at least known to decrease the risk of transmission from a symptomatic person, these had not been conclusively shown to work at preventing the acquisition of infection in uninfected individuals.

A few months into the pandemic, it became apparent that SARS-CoV-2 could be transmitted from asymptomatic persons. The early virus variants were less efficiently transmitted by asymptomatic patients compared to symptomatic ones but it was clear that asymptomatic or minimally symptomatic individuals could infect others. This led the US CDC (Centers for Disease Control and Prevention) to recommend that everyone should wear a mask. Even cloth masks were thought to offer some protection against transmission and were recommended in the light of continued shortages of PPE. The cloth mask was initially not intended to protect against acquisition of infection, but rather to decrease the amount of virus being released by asymptomatic carriers. If available, surgical masks were seen as better for this purpose. The CDC, however, continued to discourage use of medical grade respirators, such as N95s, for the general public in order to preserve these stocks for healthcare workers.

As the pandemic continued, more and more data started to show that masks worked not only to prevent transmission but also to prevent infection. When Delta and Omicron emerged, asymptomatic transmission increased significantly due to much higher viral loads. Airborne transmission was shown to occur more frequently than previously thought, and some healthcare authorities began to recommend N95 respirators for protection. A landmark study finally conclusively showed that surgical masks and respirators significantly decreased the risk of infection when worn correctly and consistently. While N95 respirators offered the highest potential protection, the efficacy of surgical masks in preventing infection overlapped with the range of protection of N95 masks, especially when surgical masks were consistently used. Given the high cost and potential discomfort of N95 masks, this led the US CDC to modify its recommendations to “wear the most protective mask you can that fits well and that you will wear consistently.”

Unfortunately, good evidence supporting the efficacy of masks in preventing infection came after the US and many countries had already started relaxing mask mandates. As early as June 2021, outdoor mask mandates in the US had been lifted because of the rollout of vaccines and increasing political polarization of mask mandates. By February 2022, indoor mask mandates had been lifted in most places, except for public transport and hospitals. Despite increasing evidence of immune evasion by the Omicron variant and cases still numbering in the hundreds of thousands, there was no longer any appetite from authorities to continue enforcing masking in most places. Things came to a head when a federal court struck down the mask mandate on public transportation, leaving it to the public and transport companies to decide whether to wear a mask. An appeal was filed and the US Supreme Court eventually ruled that the mandate was legal, but the damage had been done and very few people have continued to wear masks in the US.

The US is now dealing with a resurgence of Covid-19 cases as well as a surge in influenza and RSV (respiratory syncytial virus) infections. This “tridemic” is now clogging up their emergency rooms and hospitals, especially for the pediatric population. Masks likely work not only to prevent Covid-19, but also against most respiratory viruses. If not for the political polarization surrounding masks, widespread use could have mitigated transmission of these other viruses and decreased pressure on healthcare systems.

With the Philippines finally shifting to voluntary masking, it is important to remember that the utility of wearing masks goes beyond Covid-19. Optional masking doesn’t mean you shouldn’t wear it. It means you can still wear a mask to maximize protection not just against Covid-19 but a host of other respiratory illnesses. Cases of influenza, tuberculosis, and the common cold decreased during the pandemic, almost certainly as a result of mask mandates.

Masks as a public health intervention should be decoupled from Covid-19 as we shift to endemicity. Masks should be seen as an essential public health tool that is an effective means of preventing respiratory diseases in general. It is quite comforting to see that many people in Metro Manila have opted to keep their masks on to protect each other even after the mandate was lifted. After all, it is now very clear that masks save lives.