In USA, in view of the increasing number of people who are vaccinated and the decrease in cases of covid-19, many experts argue that the time will soon come to lift the requirement that everyone wear a mask in closed spaces. According to them, such a measure could encourage the most reluctant to get vaccinated by showing them a clear advantage of doing so.
The Centers for Disease Control and Prevention (CDC), the main public health agency in the United States, already recommends that vaccinated people do not wear masks outdoors or indoors when in small groups with other vaccinated people. .
President Joe Biden, who set a July 4 deadline for 70% of American adults to receive at least one dose, told a meeting with governors on Thursday that further easing would be forthcoming.
For now, about 59% of adults have received at least one dose, and the country registers some 38,000 new cases of covid-19 every day, that is, 11 cases per 100,000 people, a rate that continues to decline.
The consensus among experts is that, in light of these encouraging data, it may soon be possible to phase out masks in most public places.
“Those who are already fully vaccinated can wear a mask as a sign of solidarity or symbolically, but it doesn’t benefit anyone else,” says Vinay Prasad, an epidemiologist at the University of California, San Francisco (UCSF).
For them, “there is an incredibly low probability that an infection can be detected by a PCR test, much less transmitted to someone,” he adds.
At first, health authorities were cautious about the ability of vaccines to stop transmission, since clinical trials had only demonstrated their efficacy against cases with symptoms, without ruling out the possibility of infections without manifestations of the disease (fever, etc.).
But real-world data has shown that, as many immunologists predicted, vaccines are also very effective against asymptomatic cases, says Monica Gandhi, a UCSF professor of infectious diseases.
A study among healthcare workers in Great Britain showed an 86% reduction in asymptomatic cases after two doses of the Pfizer vaccine. And a large study among the Israeli population showed 94% effectiveness.
According to CDC data at the end of April, about 9,000 of the 95 million vaccinated people were infected by the virus, that is, 0.009%. The hospitalization and death rates were 0.0009% and 0.0001%, respectively.
And even when a case occurs in a vaccinated person, Israeli research shows that the viral load in the nose is very low, too low to infect another person.
“The mask is a tool, and vaccines are the solution,” says Monica Gandhi, who has written numerous publications on the importance of the mask during the pandemic, and was one of the first to promote its universal use in the United States.
“A tool is no longer useful once you have the solution, so when we reach a certain level of vaccination, it will not be necessary,” he says.
Another good reason for loosening these restrictions is to motivate reluctant people to get vaccinated, says Angela Rasmussen of the Vaccine and Infectious Diseases Organization of Canada.
This is becoming a critical problem in the United States, where the daily vaccination rate has fallen from the peak reached in April, and supply is outstripping demand.
But it will be important to establish clear numerical levels, “because one of the biggest communication problems during the pandemic was the public perception that the rules of the game established by health authorities changed over time,” says Rasmussen.
His recommendation is to lift the requirement to wear a mask inside homes in areas where fewer than two cases are registered for every 100,000 people a day, and where 70% of the population is vaccinated.
But she and others experts They believe that masks will remain a personal choice, and that it will continue to be smart to use them for older people who also have risk factors.
Amesh Adalja, who works on pandemic measures at the Johns Hopkins Center, says mask use may become seasonal. “The United States is going to become a society with many more masks, especially during flu season, indoors and in transportation,” he predicts.