Efficacy of Masks

Do Wearing Masks Really Prevent Coronavirus 

    

    For weeks, U.S. health authorities discouraged healthy Americans from wearing masks, believing they would do more harm than good. However, other countries such as China and South Korea have required all citizens to wear a mask when entering a public setting to prevent the spread of the coronavirus. But really how effective are these masks against the coronavirus? On April 3rd, Nature Medicine published an article describing their findings based off an experiment testing the efficacy of surgical face masks against coronavirus, influenza virus and rhinovirus. 

Study Findings

    Their results demonstrated that surgical masks were largely effective in reducing coronavirus transmission through respiratory droplets as well as aerosol particles. Three out of ten people who did not wear a mask were infected with the coronavirus through droplet particles. Out of eleven people who wore masks, not a single one was infected through the transmission of droplet particles. Similarly, no one who wore a face mask was infected by the coronavirus through the transmission of aerosol particles while four out of ten people who did not wear a mask were infected. The results suggest that coronavirus can be transmitted through both respiratory droplets as well as aerosol particles and wearing surgical face masks are crucial to the control of COVID-19.

(Leung, N.H.L., Chu, D.K.W., Shiu, E.Y.C. et al. Respiratory virus shedding in exhaled breath and efficacy of face masks. Nat Med (2020)

Evidence from Other Regions

    In Hong Kong, a place where citizens have been encouraged to wear masks, there is a significantly lower death rate from the coronavirus than that of the United States. Hong Kong, has had a total of 0.5 deaths/1M population. Meanwhile, the U.S., who has been previously discouraging healthy citizens from wearing masks, has a death rate of 109/1M population. (Data obtained from https://www.worldometers.info/coronavirus/ as of April 15, 2020). This data suggests that requiring the use of face masks significantly decreases the rate of death.
    

Masks Recommended by CDC

    As of April 3, 2020, the CDC is now recommending that everyone wear masks when going out in public settings. Simple homemade cloth masks are certainly more effective than wearing nothing at all in helping to slow the spread of the virus. Until supplies become more available, let us leave surgical and N-95 masks for the most vulnerable such as doctors, nurses and the elderly. Cloth masks can be easily made with household materials at a low cost. Here is a video on How to Make Your own Face Covering. You can help prevent the spread of the coronavirus by making and wearing your own homemade face mask. Although wearing masks are not the only factor to slow the spread of COVID-19, it is important that we, as citizens, do as much as we can to help contribute to flattening the curve.

Sources

1. Leung, N.H.L., Chu, D.K.W., Shiu, E.Y.C. et al. Respiratory virus shedding in exhaled breath and efficacy of face masks. Nat Med (2020).