Why Has Americans' Life Expectancy Dropped The Most Since WWII?

A sobering study released Wednesday showed that the U.S. had among the steepest declines in life expectancy among 37 high-income countries in the pandemic year of 2020.

The international study published by the U.K.-based BMJ journal, a weekly peer-reviewed medical trade journal, showed that American men saw their life expectancy drop by 2.3 years and women lost more than 1.6 years. The country experienced the highest excess mortalities among younger people between the ages of 15 and 54. According to the study, the fall in life expectancy for people in this age group was 2.3 years.

Theresa Andrasfay, a postdoctoral researcher of gerontology at USC who was not involved in the study, noted to NBC News that the loss of life was the steepest since World War II, when 418,500 U.S. servicemembers and civilians died in its four years of involvement.

The COVID-19 pandemic has taken the lives of 746,705 Americans in the last two years, according to the most recent data from the Centers for Disease Control and Prevention's COVID-19 Data Tracker.

Initially, older Americans were more likely to be infected or die from the virus as well as Black and Hispanic Americans. As vaccinations increased, the trends shifted towards more rural, white and unvaccinated Americans.

The only country to rank higher than the U.S. in experiencing a drop in life expectancy was Russia.

Recently, Russian authorities have been struggling with a surge in COVID-19 cases as numbers rise to their highest at any previous point in the pandemic. A total of 243,255 Russians have lost their lives due to COVID-19, the fourth-highest total in the world.

In comparison, New Zealand, Taiwan and Norway all saw their life expectancies increase in the last year. It is perhaps no coincidence that these countries all saw far fewer COVID deaths than many of their peers.

Iceland, Denmark and South Korea all recorded no change in their life expectancies.

“Our results strongly justify a more nuanced estimation of the lives lost,” read the report from the study's authors. “More than 222 million years of life were lost in 2020, which is 28.1 million … years of life lost more than expected.”