Even with authorities in Texas and Mississippi withdrawing mask mandates across the state, researchers at the Centers for Disease Control and Prevention on Friday offered new evidence of the importance of facial coverage, reporting that mask mandates were linked to fewer infections with coronavirus and Covid 19 deaths in United States counties.
Federal researchers also found that counties that opened restaurants for on-site dining – inside or outside the home – saw an increase in daily infections about six weeks later, and an increase in Covid-19 mortality rates about two months later.
The study does not prove cause and effect, but the findings are in line with other research showing that the masks prevent infections and that the internal spaces promote the spread of the virus through aerosols, tiny respiratory particles that remain in the air.
“You have decreases in cases and deaths when you wear masks, and you have increases in cases and deaths when you dine in a restaurant in person,” said Dr. Rochelle P. Walensky, director of the CDC, on Friday. “And then we would defend policies, certainly while we are at this level of a large number of cases, that would listen to this science of public health.”
On Friday night, the National Restaurant Association, which represents one million restaurants and eating establishments, criticized the CDC study as “an ill-informed attack on the sector most affected by the pandemic”. He pointed out that the researchers did not control factors other than restaurants – such as business closures and other policies – that may have contributed to infections and deaths from coronavirus.
“If a positive correlation between ice cream sales and shark attacks is found, it does not mean that ice cream causes shark attacks,” the association said in a statement.
The group also criticized federal researchers for failing to measure compliance with safe operation protocols and noted that the research did not distinguish between indoor or outdoor dining, or whether restaurants adhered to distance recommendations or had adequate ventilation.
“It is irresponsible to attribute the spread of Covid-19 to a single sector,” said the association.
The findings come at a time when city and state officials across the country are fighting growing pressure to reopen schools and businesses amid falling rates of new cases and deaths. Officials recently allowed limited indoor meals in New York City. On Thursday, the Connecticut governor said the state would end capacity limits later this month for restaurants, gyms and offices. Masks are still needed in both locations.
“The study is not surprising,” said Joseph Allen, associate professor at Harvard’s TH Chan School of Public Health and director of the university’s Healthy Buildings program. “What is surprising is that we see some states ignoring all the evidence and opening up quickly, removing mask orders and opening a full dinner.”
Other researchers said the new study confirmed the idea that viral transmission often occurs through the air, that the physical distance may not be enough to stop the spread in some environments and that it masks at least partially blocks the airborne particles.
President Biden’s health advisers have said in recent days that now is not the time to relax. On Thursday, the seven-day average of new cases was still 62,924 a day, according to a database maintained by The New York Times.
Although that number has dropped 14% from the previous two weeks, new cases remain close to the peaks recorded last summer. Although deaths have started to decline, in part because of asylum vaccination campaigns, it remains routine that 2,000 deaths are reported in a single day.
Biden criticized on Wednesday the decisions of the governors of Texas and Mississippi to suspend mask mandates across the state and reopen companies without restrictions, calling the plans “a big mistake” that reflect “Neanderthal thinking”.
The president, who asked Americans to wear masks during their first 100 days in office, said it was critical that public officials follow the guidance of doctors and public health leaders as the coronavirus vaccination campaign gains momentum. As of Thursday, some 54 million people had received at least one dose of the Covid-19 vaccine.
“It may seem tempting, in the face of all this progress, to try to return to normality as if the virus were in the rearview mirror,” said Andy Slavitt, a White House adviser on the pandemic, on Friday. “It is not.”
CDC researchers examined the associations between mask mandates, meals in closed or open-air restaurants and coronavirus infections and deaths last year between March 1 and December 31. and deaths.
Infections and deaths declined after counties forced masks to be used, the agency found. Daily infections increased about six weeks after counties allowed restaurants to open for dinner on site, and death rates followed two months later.
The report’s authors concluded that the masks’ mandates were linked to statistically significant reductions in coronavirus cases and mortality rates within 20 days of implementation. Dining on site in restaurants, indoors or outdoors, has been associated with increased case and mortality rates 41 to 80 days after reopening.
“State masking mandates and banning on-site dining in restaurants help limit potential exposure to SARS-CoV-2, reducing the transmission of Covid-19 by the community,” wrote the authors.
Shortly after publishing the report, the CDC amended it, urging establishments that resume service to snack bars to follow the agency’s guidelines to reduce transmission in restaurants.
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“The message is, if restaurants are going to open for on-site dining, it is important to follow the CDC guidelines to do this safely and effectively,” said Gery P. Guy, a scientist on the CDC Covid response team and corresponding author of the study .
This includes “everything from having employees at home when they show signs of Covid, testing positive or contacting someone who has Covid, and requiring masks between employees and customers who are not actively eating or drinking,” Dr. Guy said.
Other steps include adequate ventilation, options for eating outdoors, two-meter spacing between customers, encouraging frequent hand washing and cleaning of surfaces that are heavily touched, such as cash registers or payment terminals, door handles and tables.
Even though restaurants limit capacity, however, the aerosol virus can accumulate if ventilation is inadequate, said Dr. Allen.
“It doesn’t really matter if it’s a restaurant, spinning class, a gym, a choir practice – if you’re indoors without masks, with little or no ventilation, we know it’s a bigger risk,” he said. “Respiratory aerosols accumulate inside the home. It’s that simple. This is a real problem for restaurants. “
Linsey Marr, an aerosol transmission specialist at Virginia Tech, said that Americans cannot be expected to follow all the latest science, and many simply trust what is open or closed as an indicator of what is safe.
But dining indoors is particularly risky, she added. People usually sit in a restaurant for an hour or more and don’t wear masks while eating, which leaves them vulnerable to airborne viruses.
“Limiting capacity will help to reduce the risk of transmission, but indoor meals are still a high-risk activity until more people are vaccinated,” she said.
Restaurant workers are particularly exposed. Although they can use masks, customers do not, reducing protection against the virus. And workers spend many hours indoors each shift, Allen said.
He recommended that restaurant workers wear a double mask, wearing a surgical mask covered by a cloth mask, or purchase high-efficiency masks such as N95s, normally reserved for healthcare professionals, or KN95 or KF94 masks, taking steps to ensure that they do not were false.
“Now is not the time to let your guard down and pull the controls when we are so close to vaccinating many people,” said Allen.
Eileen Sullivan contributed reporting.