Ômicron reinforces the importance of masks and the use of more efficient protection

With the discovery of Covid’s omicron variant, the importance of masks in combating the coronavirus pandemic has regained attention. This happens exactly at the time when the most debate in Brazil was to relax the mandatory use of protection — especially in outdoor environments, where, in theory, the risk of contagion is less.

The loosening of the obligation (but not of the masks, which must always be well adjusted to the face) for open spaces already has a date in the state of São Paulo: December 11th. Or had, considering that, after the confirmation of the first cases of omicron in Brazil, the João Doria government (PSDB) has already asked for a new study on flexibilization.

According to specialists, as happened before, once again, it is time to reinforce the importance of using masks, in addition, of course, to the need for vaccination against Covid.

“Everyone still wears a mask”, says Raquel Stucchi, a professor at Unicamp and a consultant at the SBI (Brazilian Society of Infectology). “Let’s continue with what we’re used to.”

Gerson Salvador, an infectious disease specialist at the University Hospital of USP, emphasizes that “the means of transmission and prevention do not change”.

The effectiveness of this facial barrier for protection against Sars-CoV-2 —whatever it is— and against its spread has already been demonstrated by studies.

But of course there are differences depending on the masks and how they are used. Masks that do not cover the nose or are worn on the chin, of course, make no difference. The material also impacts protection.

A study by USP pointed out the filtering efficiency of various types of masks available in Brazil. N95 or PFF2 are the most suitable, with an efficiency above 98%. Then appear TNT or surgical (between 80% and 90%). Then, the cloth ones, with an average of 40%. Knit masks, with open weaves or synthetic fabrics such as lycra and microfiber are not effective for protection.

Another study, this time by the International Monetary Fund, estimates how many lives were saved by wearing masks, based on the rules for using protection in the United States.

According to the American survey, it is estimated that the mandatory use of masks has preserved about 87,000 lives and potentially could have saved the lives of more than 58,000 Americans — if mandatory use were extended to the entire country.

“Mandatory mask use should remain an important tool against Covid,” the August survey said. “Furthermore, masks could be essential to fight future pandemics.”

The omicron has dozens of mutations in its S protein (Spike). Available data so far indicate that it has greater potential for dissemination and reinfection in people who have already had Covid.

The situation points to the need for masks with greater filtration potential, says Stucchi. In other words, the N95, which can even be reused for a long time, if used with due care.

In addition to reinforcing the role of vaccination, Leonardo Weissmann, a consultant at SBI, also says that “N95 can bring greater protection at a time when we know little about the omicron”.

Apart from the measures that are already standard to fight the pandemic, such as well-ventilated spaces, vaccines and masks, Salvador also defends the requirement of vaccine passports for those coming from outside Brazil (the first confirmed cases of omicron in the country are associated with people without vaccination history against Covid) and for indoor access.

Salvador also says that it makes no sense to block the entry of travelers from some countries, when the new variant has already been found in several countries.