Until A COVID-19 Vaccine Emerges, Can Masks Be A Kind Of Vaccine Against Coronavirus?
While the wait is on for a safe and effective coronavirus vaccine, a hypothesis emerges of a different kind of "vaccine" — your face mask.
“Mask up” is the slogan going around as cases of the coronavirus disease, Covid-19, remain high and restrictions on public activity fall. The role of the mask is to protect you and others from the transmission of SARS-CoV-2, the coronavirus behind the pandemic.
However, a new idea suggests that masks may do more than just offer protection — they may act as a “crude vaccine” until an actual vaccine emerges.
The hypothesis has been in The New England Journal of Medicine (NEJM).
The report says “...universal masking could become a form of “variolation.”
This term refers to a method prevalent in pre-vaccine times. Individuals were immunised against smallpox by exposing them to viral material taken from patients with a mild form of the disease. The name “variolation” came from the name of the virus causing smallpox, variola.
In the coronavirus context, the idea is that the mask would allow a small amount of the virus to seep through, keeping illness to a minimum while inducing an immune response in the body against the alien pathogen. The new battalion of immune cells, specifically T cells, would keep guard against the coronavirus and launch an attack the next time it comes around.
The result would be an overall rise in the immunity levels in the population, making it harder for the virus to locate susceptible people to infect. In this way, the virus spread would slow down.
Whether the virus would eventually die out or remain in action one place or another, at one time or another, will depend on how long our adaptive immunity can keep us safe. But we won’t have to worry about how long the mask will protect us — one or more safe and effective vaccines are expected to arrive next year. The mask can hold fort only till then.
This is a hypothesis yet to be borne out in a trial. The only way to test this idea is to have two groups — one with masks, other without — participate in an experiment that exposes them to the virus, and then observe the outcomes. Such a study would raise ethical alarm bells.
Some of the parameters to watch out for and compare in tests would be the level of illness (between masked and unmasked), the strength and durability of T-cell immunity specific to SARS-CoV-2 (between symptomatic and asymptomatic), and infection spread (between areas with different levels of infection). This would provide clarity on the hypothesis.
In the absence of a clinical trial in humans, the idea gets its oxygen from past experience with pathogens and a theory of viral pathogenesis that says disease severity is dictated by the amount of viral material in the body. The less the virus, the less will be the disease severity.
In animals, this relationship between viral inoculum and disease severity with respect to coronavirus has been established. The NEJM report makes note of this study, in Clinical Infectious Diseases journal at the end of May. Two sets of hamsters were kept apart by a surgical mask partition in the investigation. It was observed that SARS-CoV-2 transmission was reduced with the help of the partition.
In humans, the benefits of universal masking have borne out in numerous studies — a higher proportion of people end up asymptomatic or mildly symptomatic if everyone has their masks on as compared to cases when everyone doesn’t.
Still, direct evidence for the theory of a mask acting as a crude vaccine doesn’t yet exist.
In the absence of standard proof, therefore, the protocol remains the same — wear a mask, keep a safe distance, avoid crowds, and wash hands regularly.
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