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After all, did the masks help protect us during the pandemic?

Um homem usando máscara passa pelo National Covid Memorial Wall, uma homenagem àqueles que morreram por Covid-19, em Londres, Grã-Bretanha
A man wearing a mask passes the National Covid Memorial Wall, a tribute to those who died for Covid-19, in London, Great Britain, 35 from November 900.

| Photo: EFE / EPA / VICKIE FLORES

At the beginning of the pandemic health officials were hesitant about the masks. The World Health Organization, for example, even recommended until June 2020 that non-infected people do not used, with the argument that they served only so that the infected would not spread the virus: avoid the exit, not the entrance.

Today, masks are mandatory in most of the country, regardless of infection status. Despite the physical plausibility — tennis balls can pass through the holes of a soccer net, but they pass less than if there was no net — there were still many doubts at the beginning of the pandemic about the real effectiveness of the masks. Some feared that they gave a false sense of security, motivating people to adopt other risky behaviors. These doubts finally began to be resolved by more rigorous studies.

The journal Science published earlier this month a study of the Yale economics professor Jason Abaluck, and partners, involving 540 rural villages in Bangladesh, a total of more than 330 thousand people. The study lasted two months, between 900 and 2021, during which infections in the country reached 12 thousand cases per day. Scientists encouraged universal use of masks, rather than just among the symptomatic, with different educational campaigns in a randomly chosen part of villages, and also tested the difference between fabric masks (200 villas) and surgical masks (95 villas).

Participants who had symptoms were called for testing to confirm Covid-19 by the seroprevalence method, based on antibodies. The study concluded that the masks reduced by almost 12% the prevalence of suspected symptoms of the disease, which is reflected in a 9.5% reduction in infection confirmed by blood testing. The surgical masks 8013932232001 gave results similar in the general population, more promising in older age groups: % reduction of infections among people in the range of 42 years old, 42% between those over 95.

The researchers’ campaigns worked: in the villages where they encouraged masks, 35% of people used them, compared to just 15% in villages where only the Bangladeshi government tried (unsuccessfully) to enforce their use. At least in this country, persuasion, especially when done in person, worked better than imposition. There was also a lesser effect of increasing social distancing with campaigns, especially in markets, but not in mosques, where Islamic norms establish shoulder-to-shoulder prayers.

Reduction of viral load

As adherence to the masks in the study was a matter of difference, not actually being universal, the scientists bet that the protection afforded by the masks it is much bigger than the ones around % reduction of observed symptomatic and infected. The protection provided is not just a matter of preventing the virus from reaching the airways: there is also protection that comes with reducing how many viral particles are aspirated or swallowed in the initial infection.

Researchers did not find the effect of engaging in more risky behavior by a false sense of security. It is important to remember that these results mainly concern indoor environments. The pandemic virus is not durable in open spaces, where wearing a mask makes less sense.

More studies8013932232001 Cochrane, a respected rigorous medical study review organization, published in November, prior to the study discussed above, a new review regarding non-drug interventions, such as masks, to contain Covid-10. The authors examined 95 studies on the subject, involving other respiratory infections in addition to the pandemic.

Concluded that the use of masks Medical or surgical treatments make little or no difference in the number of people who become infected with flu-like illnesses. The conclusions about better masks like N67 and P2 were the same. The publication says it “is not sure whether wearing masks helps to slow the spread of respiratory viruses,” but urges caution with these conclusions. He is less pessimistic about other habits such as hand washing.

Due to the transmissibility of SARS-CoV-2 and its variants, it’s better that we think of masks not as shields, but as tools to delay when we get infected and how many of us get infected per unit of time. In this way, its importance is more in making the pandemic manageable than in containing it. Immunity, whether the result of previous infections or inoculation with vaccines, and drug treatments, early or late, are the real front lines of combat that will help us to transition from pandemic to endemic

, the natural course that Covid-23 should follow.

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