How do masks protect us from viruses?
2:44
(CNN Spanish) -
A new scientific study published in the prestigious New England Journal of Medicine speaks of the additional benefit of the use of masks during the covid-19 pandemic.
They could act as a variolation element, that is, generate a kind of immunity to the virus.
In this episode, Dr. Elmer Huerta analyzes the study and refreshes us on the term variolization.
You can listen to this episode on Apple Podcasts, Spotify, or your favorite podcast platform, or read the transcript below.
Hello, I am Dr. Elmer Huerta and this is your daily dose of information about the new coronavirus, information that we hope will be useful to take care of your health and that of your family.
Today we will see what other advantage, in addition to avoiding contagion, offers the use of the mask.
The use of masks to prevent the spread of the new coronavirus was rapidly and massively adopted by the population of Asian countries.
It is believed that previous experiences with epidemics were very influential in their immediate adoption of the use of masks.
The Western world, however, has gone through various moments in its adoption.
The use of masks
At the beginning of the pandemic, and following the recommendations of the World Health Organization and the Centers for Disease Prevention and Control of the United States, the use of the mask was only recommended for people with symptoms of a respiratory disease .
It was not until April 3 that the CDC changed its position, and recommended that the entire population of the United States wear a mask to prevent those individuals who have the new coronavirus without knowing it, or have symptoms, from infecting others.
WHO took much longer.
It was only on June 5 that he changed his position and also recommended the universal use of masks.
Meanwhile, because of this delay and political ups and downs, the mask became, in the United States at least, a sign of political division.
The point is, as we described in the April 26 and June 23 episodes, that masks have proven to be essential elements in preventing the spread of the new coronavirus.
In that sense, masks not only act as a physical barrier so that the person who uses them does not get infected.
Rather, it does the reverse work, that is, it prevents a symptomatic or asymptomatic person from infecting others.
But now, researchers at the University of California in San Francisco raise an interesting hypothesis published in the New England Journal of Medicine on September 8, which establishes that masks act as an element of variolization, causing that if we get infected using it, the disease that we acquire is asymptomatic.
Let's see what that old concept of variolization consists of.
What is variolization?
Smallpox was, since ancient times, a plague that affected all layers of society.
In the 18th century in Europe, 400,000 people died annually of smallpox and a third of the survivors went blind.
Most of the survivors were left with disfiguring scars and between 20% and 60% of the patients died.
In young children, mortality was even higher, estimating that at the end of the 19th century it reached 80% in London and 98% in Berlin.
Due to its high mortality and severe aesthetic consequences, humanity has tried since time immemorial to develop some type of preventive treatment against the disease.
Somewhere in Africa, China, or India, medical practitioners are thought to have developed a method of controlling the disease, which they called variolization, based on the observation that a person suffering from the disease became immune to she, that is to say, never got sick again.
Immunity from exposure
Motivated by unknown reasoning, variolization consisted of obtaining fresh material from the blisters caused by smallpox and injecting them by scraping into the skin of healthy people to avoid the disease.
Common practice in Asia, variolation reached Europe in the early 18th century, led by the aristocratic classes of the English court.
Despite variolization causing illness and death in some subjects subjected to it.
These figures were much lower than those caused by natural disease, so its practice spread in Europe and America, and became the main way to combat this serious disease.
It was in 1796, when the English physician Edward Jenner observed that women who milked cows and acquired cowpox were also immune to human smallpox, that the vaccine was invented, making it possible for smallpox to be eradicated from the world in 1975.
But going back to variolation, this was a method that did not completely eliminate smallpox;
what it did was decrease the intensity of the disease.
In other words, the variolized person developed smallpox so mild that the damage caused by the disease lessened.
Do masks generate immunity to covid-19?
Returning to masks, researchers at the University of California postulate that the use of masks during this COVID-19 pandemic would act as an element of variolization.
That is, if a person becomes infected using a mask, the viral load would be so low that it would end up causing an asymptomatic form of the disease.
In this sense, they mention that in societies where the use of masks is almost universal, the proportion of asymptomatic cases is 80%, while in societies where the use of masks is not generalized, the proportion of asymptomatic cases is of the 40%.
They also cite two situations in which the masks produced a high number of asymptomatic cases.
The first in an Argentine ship and the second in a meat processing plant, in which, thanks to the masks, distributed very early in the outbreak, the proportion of asymptomatic patients reached 81% and 95%, respectively.
Obviously, the researchers say, their hypothesis could only be tested by comparing the proportion of COVID-19 cases in societies that wear and do not wear masks, something very difficult to do.
In summary, the hypothesis is very attractive and adds another potential benefit to the use of masks to prevent disease.
Do you have questions about covid-19?
Send me your questions on Twitter, we will try to answer them in our next episodes.
You can find me at @DrHuerta.
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Thanks for your attention.
If you have any questions you can send them to Dr. Elmer Huerta via Twitter. You can also head over to CNNE.com/coronaviruspodcast for all episodes of our “Coronavirus: Reality vs. Reality” podcast. fiction".
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