Use of face masks may be inadvertently giving some people COVID-19 immunity.
A commentary in the respected New England Journal of Medicine suggests mask-wearing might be reducing the severity of the virus and ensuring a greater proportion of new infections are asymptomatic.
Evidence of this, say the authors, can be found in an outbreak on a closed Argentinian cruise ship, “Passengers were provided with surgical masks and staff with N95 masks … the rate of asymptomatic infection was 81% (as compared with 20% in earlier cruise ship outbreaks without universal masking). In two recent outbreaks in U.S. food-processing plants, where all workers were issued masks each day and were required to wear them, the proportion of asymptomatic infections among the more than 500 people who became infected was 95%, with only 5% in each outbreak experiencing mild-to-moderate symptoms.”
Infectious Disease physician, Dr. Monica Gandhi (University of California, San Francisco) – one of the paper’s authors – has stressed the commentary should not be construed as anything other than a theory.
While their theory is cause for optimism, Gandhi said much more study is required.
Still, with test results on a vaccine pending, the authors say any public health measure that could increase the proportion of asymptomatic infections may make COVID-19 less deadly and increase population-wide immunity without severe illnesses and deaths.