A sign on a downtown Portland business door tells customers a face mask is required for entry on Dec. 9, 2021. Credit: Troy R. Bennett / BDN

During the COVID-19 pandemic’s early days, it wasn’t crystal clear how well face masks were preventing coronavirus infections or severe disease among wearers. Now, a new study reveals an association between mask policies and reduced COVID-19 deaths long before vaccines were added to the picture.

Research on 44 countries in Asia and Europe including nearly one billion people shows nations that enacted face mask policies at the start of the pandemic had significantly lower COVID-19 deaths per million people than those that did not enforce any mask rules.

Mask policies in the U.S. and Canada were not included in the study because such actions were made at the state or province level, not at a national one, researchers said in their study published last month in the American Journal of Preventive Medicine. Countries involved in the study included Greece, Germany, Korea, Italy, the U.K., Sweden and Hong Kong, among others.

There were more than 1.2 million confirmed COVID-19 deaths in countries without mask policies and nearly 914,000 in those with the policies between February and May 2020; average COVID-19 mortality rates per million people stood at 48 and 288, respectively.

Overall, increases in daily deaths were “significantly lower” in countries that enforced mask policies, suggesting face coverings did and do  offer an additional layer of protection that “could prevent unnecessary COVID-19 deaths,” researchers said in a news release posted Dec. 15.

The findings also emphasize the important role face masks play in regions that still don’t have access to COVID-19 vaccines, researchers say, especially as more dangerous variants continue to emerge and spread.

“Across variants, vaccines may reduce mortality but not necessarily morbidity, and face masks continue to protect against both,” lead study investigator Dr. Sahar Motallebi of the department of social medicine and global health at Lund University in Sweden, said in the release. “So, we don’t have to choose between these two good policies of vaccination and face masks or substitute one for the other when we can and must do both in parallel.”

The research team selected countries for their study based on the top 50 nations listed by the “United Nations Development Program Human Development Index,” which measures “life expectancy, education and standard of living;” 27 countries had face mask policies and 17 did not.

Only COVID-19 deaths that occurred between February and May 2020 were analyzed because the months marked the time of the first confirmed deaths and when countries began lifting coronavirus restrictions.

To the researchers’ surprise, countries with no mask policies started out with lower COVID-19 death rates, but over time, they accelerated quickly and surpassed rates in countries with mask policies.

“While several studies before this have looked at the impact of masks on COVID-19 cases, fewer studies were focused on whether mask wearing may reduce COVID-19 deaths, and no study had looked at the data across multiple countries,” Motallebi said in the release. “The large sample of culturally diverse countries in this retrospective study covers a large population, giving us more evidence towards the life-saving potential of masks during the COVID-19 pandemic.”

Katie Camero, McClatchy Washington Bureau