(CNN) — Another 134,000 people could die in the US from Covid-19 by December if no further safety measures are mandated — and the actual number probably would be much worse if mandates are relaxed, researchers say.

The projection by the University of Washington’s Institute for Health Metrics and Evaluation comes with a silver lining: About 70,000 of those lives would be saved if many more Americans wore masks, the institute’s leader said.

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“It really depends on what our leaders do, (both) as individuals, and what governments do,” the IHME’s chief, Dr. Chris Murray, told CNN’s Anderson Cooper on Friday night.

At least 176,000 people have died of Covid-19 in the US since the pandemic began, and more than 5.6 million have been infected, according to data from Johns Hopkins University.

IHME projected that if nothing about the nation’s approach to prevention changed, death rates would dip in September but rise later in the fall, and the total would reach about 310,000 by December 1.

But changes in behavior would affect the projection, he said:

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  • If governments ease current social distancing restrictions and mask mandates, daily death rates could reach 6,000 daily by December, up from his current prediction of 2,000 daily, Murray said.
  • On the other hand, if significantly more people wore masks, the projection of total deaths from now to December would drop by almost 70,000, he said. About 95% of the US population would have to wear masks for that to happen, he said.

Coronavirus case rates have been dropping for weeks in parts of the US, but death rates have been relatively elevated.

The country’s seven-day average for daily coronavirus deaths was 987 on Friday — the first time in more than three weeks that it dipped below 1,000, according to Johns Hopkins University data.

Daily US cases over the past week averaged about 44,100 as of Friday, down from a peak average of 67,317 on July 22, John Hopkins data show.

US Centers for Disease Control and Prevention Director Dr. Robert Redfield said earlier this week he expects deaths to begin declining by next week as a result of continued mitigation measures.

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