Masks Could be Giving People COVID-19 Immunity

With anti-mask protests continuing around the country and in many other parts of the world, it seems that there are plenty of people still not convinced that masks work. However, research continues to suggest otherwise and a new article published in the New England Journal of Medicine (NEJM) is adding weight to the promising theory that widespread face mask wearing could generate immunity.

Reducing the Severity of Symptoms

Recent virologic, epidemiologic, and ecologic data have led researchers to develop the hypothesis that face masks can reduce the severity of the disease among those that become infected with it. Research outlined in the NEJM suggests that universal mask-wearing might help reduce the severity of COVID-19 infections and help ensure that a greater proportion of new cases are asymptomatic. 

If this is the case, wearing a mask could generate immunity, and this could slow the spread of the virus and reduce deadly outcomes in the US and further afield until we have a vaccine.

Evidence for the Efficacy of Face Masks

The scientific community has been proving the importance and efficacy of face masks since as far back as March when it became clear that presymptomatic and asymptomatic patients were spreading the virus via their noses and mouths at an equivalent rate to symptomatic patients. 

Previous research has shown that coronavirus cases would fall if 80% of people wore masks, and various studies suggest that mask-wearing might be a way of preventing transmission from asymptomatic infected people. As such, the Centers for Disease Control and Prevention (CDC) has been recommending the use of cloth face coverings in public places since April. 

Evidence related to past respiratory viruses also indicates that face masks can protect the wearer from becoming infected by blocking viral particles from entering the nose and mouth. More recent data from Boston demonstrates that COVID-19 infections decreased among healthcare workers once universal masking was implemented in hospitals.

Universal Masking Might Promote Immunity

The theory that universal masking could reduce the severity of the disease is fitting with the scientific community’s long-standing theory of how viruses work, in that the severity of the disease is proportionate to the viral inoculum (the material used for inoculation). Researchers have been exploring this theory since 1938, and recent studies conducted with a hamster model demonstrated that administering a higher dose of COVID-19 led to a more severe manifestation.

If this is the case, it adds another hypothesized reason for wearing masks: to reduce the viral inoculum that the wearer is exposed to, therefore reducing the severity of the infection if they contract it. This is because masks can filter out some of the droplets that contain and spread the virus, which might reduce the inoculum that an exposed person inhales. 

If this theory is accurate it means that if we all wear masks it could lead to an increase in the proportion of cases that are asymptomatic. There seems to be evidence to back this up, too. In mid-July, the CDC estimated that 40% of COVID-19 cases were asymptomatic. However, in places where universal mask-wearing is in place, this increases to 80%. Countries where mask-wearing is more culturally ingrained and widely observed have fared much better in terms of severe COVID-19-related illnesses and death. Japan has reported under 80,000 cases and just 1,451 deaths, and in Vietnam, there have only been just over 1,000 cases with 35 deaths. In both countries, the use of masks was widespread before the pandemic and has continued to be during the battle against COVID-19.

COVID-19, Masks, and the Future

The medical community agrees that the clearest way to reduce the devastating effects of COVID-19 is to reduce transmission and the severity of the illness. Eradicating the virus is proving difficult, even in regions where control measures have been strict, and efforts for widespread testing have seen varying success. 

As such, a vaccine increasingly seems like the only hope for a future without COVID-19. Despite efforts to rush potential candidates through clinical trials, it seems that we’ll likely be waiting a while longer until one is widely available. While we're wait for this to happen, we can do our part to reduce transmission and deadly infections by wearing a mask in public places.

Learn more about the article from the NEJM here: