Other states lifting mask orders are trending better, but on Wednesday, CDC Director Rochelle Walensky, MD, said they are not out of the woods, either.

“Please hear me clearly: At this level of cases, with variants spreading, we stand to completely lose the hard-earned ground we have gained,” she said in a press briefing. “These variants are a very real threat to our people and our progress. Now is not the time to relax the critical safeguards that we know can stop the spread of COVID-19 in our communities, not when we are so close,” she said.

Speaking at a Mexican restaurant in Lubbock on Tuesday, Governor Greg Abbott said the success of the vaccines along with falling case counts and declines in hospitalizations made it clear that state mandates were no longer needed.

“Removing state mandates does not end personal responsibility,” he said. “Personal vigilance to follow the safe standards is still needed.”

The problem with that stance, say researchers, is that it’s not enough. The benefit of masks depends on everybody wearing them. Studies have shown that requiring the use of masks makes a difference.

“There’s just overwhelming science on this,” said Jeffrey Levi, PhD, professor of health policy and management at the Georgetown University School of Public Health. “When mask mandates are imposed, infection rates go down and when mask mandates are lifted, infection rates go up. I mean, we’ve had enough natural experiments over the last year for us to see the impact that this has,” Levi said.

“This is a tragic politicization of our response to the pandemic and the consequences will not be limited to those states,” Levi said.

A study published last month by scientists at the CDC compared the rate of growth in COVID cases across more than 3,000 U.S. counties between June and October of last year. Those with mask mandates were 43% less likely to see a rapid growth in their infections compared to those that didn’t have them.

“Mask mandates can play a substantial role in preventing COVID-19 and could be especially important for persons who are required to work in-person, including essential workers and those working in crowded conditions, particularly in nonmetropolitan areas,” the study authors wrote.