The life expectancy of Native Americans in the United States dropped by a shocking 4.7 years during the COVID-19 pandemic, about three times that of whites and by far the most of any ethnic group, according to new research by the University of Colorado Boulder.

The study also found that the United States experienced even higher death rates in 2021, while its peer countries around the world appeared to rebound from a historic 2020 dip in life expectancy.

"With the wide availability of vaccines in the United States, there was a lot of optimism that 2021 would look better than 2020," said co-author Ryan Masters, an associate professor of sociology, in a university release on Thursday.

"That did not happen. The U.S. didn't take COVID seriously to the extent that other countries did, and we paid a horrific price for it, with black and brown people suffering the most," he said in the press release.