Universal use of a mask could prevent nearly 130,000 deaths from Covid-19, the disease caused by the coronavirus, in the United States until next spring, scientists reported on Friday.
The findings follow a claim by Dr. Scott W. Atlas, the president’s scientific adviser, that the masks are ineffective, in a tweet that was subsequently removed by Twitter for spreading disinformation. On Wednesday, the Centers for Disease Control and Prevention released new guidelines recommending the use of the mask in public places, including public transportation.
A wave of infections, partly due to failure to adhere to safety measures, has started to overwhelm hospitals across much of the country. More than 75,000 new cases were reported in the United States on Thursday, the second-highest nationwide daily total since the start of the pandemic. Eight states have single-day case records.
Those numbers are likely to continue through fall and winter, with cases and deaths steadily increasing through January and remaining high afterward, said Christopher Murray, director of the Institute for Health. Metrics and Evaluation at the University of Washington and senior author. of the report.
“We strongly believe that we are heading into a pretty gloomy winter season,” said Dr Murray.
The new study, published in the journal Nature Medicine, also offered a rough estimate of the pandemic’s toll in the United States: perhaps 500,000 deaths by March 2021, even with social distancing mandates restored in most states. .
Other experts have warned that, as with any model, the new estimates are based on many assumptions and should not be viewed as predictions.
“This is not a prediction or a forecast because we can take that number off,” said Shweta Bansal, an infectious disease modeler at Georgetown University who was not involved in the new work.
Instead, she said, the model should be viewed as a “sophisticated thought experiment” whose conclusions can change dramatically if people change their behavior.
“I would like people to see this study as a call to action, a kind of wake-up call, especially for people who are unconvinced by the devastation caused by this pandemic,” she said.
Epidemiological models that attempt to predict trends in the future, like the new one does, are particularly prone to flaws “given the dynamics of the situation and how quickly things can change,” added Ashleigh Tuite, a modeler. of infectious diseases at the University of Toronto.
Still, she and others have said the numbers look reasonable as a rough estimate of the toll by March 2021 if current trends continue.
Dr Murray and his colleagues analyzed the number of cases, testing rates, use of masks and cell phone data to estimate the movement of people from the first recorded case in each state through September 21. They then estimated the death toll through March 2021 for each state, with or without a social distancing and mask use warrant.
While many states continue to roll back existing warrants, the team said the death toll by Feb.28 could exceed one million, with a third in California, Florida and Pennsylvania.
More likely, states could reinstate distancing warrants when daily deaths hit a threshold of eight deaths per million. That would result in 511,373 deaths by the end of February 2021, according to the model.
Other models do not look as far into the future or have not taken seasonality into account and have underestimated the number of deaths that could result, Dr Murray said.
Such models “fuel the poorly science-based opinions circulating that the epidemic is over or the worst is behind us,” he said. “And that’s a pretty risky strategy.”
But Dr Tuite said she was unsure whether, even taking seasonality into account, deaths would peak in the spring, as the model estimates. Dr Murray’s model does not take into account the treatments currently available for people in hospital, she added.
For example, deaths among hospitalized patients fell to 7.6% from 25.6% in the spring, according to a study.
The new research is based on other flawed assumptions, Dr Bansal said. The model offers estimates for individual states but does not account for variations based on age or location within states, and the numbers are based on limited testing and death data at the onset of the pandemic.
Due to these and other assumptions, the estimated number of deaths is at best an approximation. Still, the figure highlights the need for individual and population-wide precautions.
Dr Murray and his colleagues have shown that the use of masks, in particular, has a huge impact, reducing the risk of infection by about half at the individual and population level.
As of September 20, just under half of Americans said they still wear a mask. But the regular use of masks by 95% of the population would save 129,574 lives, according to the new analysis. Regular use of masks by just 85% of Americans could prevent 95,814 deaths by March 2021, possibly avoiding restrictive lockdowns, Dr Murray said.
“Increasing the use of masks is one of the best strategies we have right now to delay the imposition of social distancing warrants and all the economic effects of that, and save lives,” he said. declared.
Mask warrants and sanctions for not wearing a mask may increase the number of people wearing masks, he suggested.
The mask estimates are also likely to be rough approximations, but even so, said Dr Tuite, “the qualitative conclusion is really important, that is, it has an impact, and an impact of ‘a much less disruptive way than locks or the like. more restrictive types of interventions. “
Masks are an effective and inexpensive tool to stem the spread of the virus and yet they have unfortunately become politicized, like many others in the pandemic, said Dr Carlos del Rio, an infectious disease expert at Emory University at Atlanta.
“If you wear a mask, you are a Democrat,” he said. “If you don’t wear a mask, you are a Republican. And I think that’s what’s wrong at all.
“The fact that we continue to make masks as a political issue is really upsetting,” he added, “because frankly I don’t want to see people die.”