The U.S. Centers of Disease Control and Prevention released a study that found states that issued mask mandates saw a decrease in COVID-19 cases, but when those same states allowed relaxed restrictions last year, they saw a subsequent increase in new infections.
The study observed data collected from 39 states that issued a statewide mask mandate starting in April 2020. The states studied had also discouraged close in-person contact by shutting down dining indoors at restaurants and closing non-essential businesses.
Data collected found that the states that had mask and restaurant rules in place saw a significant decrease in COVID-19 cases, which offered a false sense of security, leading to many states rolling back restrictions in June of 2020, according to the study.
FILE - A person holds a stack of masks.
"Mask mandates were associated with decreases in daily COVID-19 case and death growth rates 1–20, 21–40, 41–60, 61–80, and 81–100 days after implementation. Allowing any on-premises dining at restaurants was associated with increases in daily COVID-19 case growth rates 41–60, 61–80, and 81–100 days after reopening, and increases in daily COVID-19 death growth rates 61–80 and 81–100 days after reopening," according to the study.
Between March 1 and Dec. 30, 2020, 2,313 (73.6%) of the 3,142 U.S. counties with mask mandates saw a 0.5% decrease in daily COVID-19 cases. By the 100th day since mask mandates were implemented, counties saw a 1.8% overall decrease in daily cases.
Deaths also gradually decreased in association with data related to statewide mask mandates, with an overall 1.9% reduction in COVID-19 deaths by the 100th day, the study said.
But when states started to ease back on restrictions and allow dining at restaurants, data collected found that 3,076 (97.9%) U.S. counties only saw a slight increase in daily cases at 1.1%. More significantly, death rates increased by "2.2 and 3.0 percentage points" leading up to 100 days since the rollback.
The emergence of more transmissible coronavirus variants combined with states rolling back restrictions could lead to a fourth surge in cases, health experts have warned.
"Community mitigation policies, such as state-issued mask mandates and prohibition of on-premises restaurant dining, have the potential to slow the spread of COVID-19, especially if implemented with other public health strategies," the study concluded.
In a White House COVID-19 press briefing on Friday, Dr. Rochelle Walensky, director of the CDC, drove the point home further, referencing the agency’s recent study and repeating the warnings health experts are stressing to the public — it’s time to double down.
"The current numbers remain concerning. Cases and deaths are still too high and have now plateaued for more than a week at levels we saw during the late summer surge following six weeks of steady declines," Walensky said. "This is why I’m asking you to double down on our prevention measures. I know the idea of relaxing mask wearing and getting back to everyday activities is appealing, but we’re not there yet. And we have seen this movie before. When prevention measures like mask mandates are rolled back, cases go up."
New daily cases continue to hover between the 60,000-70,000 range and deaths remain at 2,000 per day as of Friday, according to Walensky.
Walensky stated that the study serves as a warning for states that are prematurely easing restrictions.
"There’s a light at the end of this tunnel, but we must be prepared for the fact that the road ahead may not be smooth. And that path is within our control," Walensky said. "By continuing to wear masks and following CDC’s public health recommendations while we get more people vaccinated, we can bring this pandemic to an end."
Several states have eased restrictions on businesses, allowing people to physically dine at restaurants as well as no longer limiting building capacity. States such as Texas and Mississippi have gone even further and done away with their statewide mask mandates entirely.
President Joe Biden called out state leaders, specifically in Texas and Mississippi, for their "Neanderthal thinking" in rolling back health measures amid the ongoing pandemic.
"We are on the cusp of being able to fundamentally change the nature of this disease," the president said Wednesday. "The last thing we need is Neanderthal thinking that in the meantime, everything’s fine, take off your mask, forget it. It still matters."
Walensky made assurances Friday that the CDC would soon be releasing guidance on how fully vaccinated individuals might safely socialize in small groups.
"I know there have been many questions about when CDC is going to release its guidance of fully vaccinated persons and activities they can resume," Walensky said. "These are complex issues and the science is rapidly evolving. CDC is working to ensure that the communication we release on this guidance are clear and that the American public can act on them."
"Our goal and what is most important is that people who have been vaccinated, and those not yet vaccinated, are able to understand the steps they can take to protect themselves and their loved ones," Walensky said. "We are making sure and taking the time to get this right, and we will be releasing this guidance soon."
The Associated Press contributed to this report.