Saturday, September 12, 2020

Masks and Herd Immunity

 You can wear a mask and still get COVID.  The mask is not fool-proof, but masks can reduce the viral load you are exposed to.  With a smaller viral load, you may get COVID, but it is likely to be much milder than if you got a full blast of the virus.

A new commentary by researchers in the New England Journal of Medicine speculates that masks may be helping develop herd immunity.  People who wear masks are still getting COVID, but they are often either asymptomatic or have only mild symptoms.  Mask wearing allows the spread of a mild form of the the disease and resulting immunity through the population and is preferable to people without masks, getting larger viral loads and becoming much sicker.

In other words, in areas where people wear masks, they are speculating that a larger number of infections will be asymptomatic than in areas that don’t don’t because of people getting the virus from smaller loads of the virus.

Facial Masking for Covid-19 — Potential for “Variolation” as We Await a Vaccine

It should be emphasized that the authors are not recommended mask wearing as a substitute for an effective vaccine, only suggesting that mask wearing is assisting in the development of herd immunity.

The paper represents just a theory.  It is supported by animal research that showed animals who received larger loads of virus were sicker than those animals exposed to smaller doses and research that animals (hamsters) who wore simulated masks were less likely to get COVID and when they did they were less likely to be sick than those hamsters without the simulated masks.

The authors point out that conducting similar research on humans would be unethical.  But studies of populations during COVID have shown that in those areas where mask wearing is more prevalent, there are more asymptomatic infections.

They also site examples from both cruise ships and meat-packing plants where people wore masks versus those where they didn't, the asymptomatic rates were much higher in the mask wearing groups.

The authors conclude:

Ultimately, combating the pandemic will involve driving down both transmission rates and severity of disease. Increasing evidence suggests that population-wide facial masking might benefit both components of the response.

Wear your masks!

Are Masks a Kind of Vaccine Against COVID-19?