The findings don’t prove cause and effect, but the statistically significant patterns are in line with previous studies and expert advice
For the better part of a year, now, public health experts have been clear: wearing masks helps mitigate the spread of the novel coronavirus, and indoor and outdoor dining both carry risks of transmission.
But here’s one more study, published by the Centers of Disease Control and Prevention (CDC) on March 5, to add to the growing pile of evidence out there. Examining county-level data from March 1 to December 31, researchers found mask mandates were linked to decreases in daily infections and death growth rates within 20 days. The data also showed that reopening restaurants for on-premises dining was followed by a rise in infections and deaths six to 11 weeks later, especially when mask mandates weren’t in place.
The findings don’t prove cause and effect, but the statistically significant patterns are in line with previous studies and expert advice. Masks can reduce the amount of infectious droplets and aerosols emanating from people’s noses and mouths. Indoor dining, even with limited capacity, can still allow the buildup of these infectious aerosols inside restaurants — especially without proper ventilation — as customers spend long periods of time eating, drinking, and talking without their masks on. (Restaurant workers face the most risk in these scenarios.) Outdoor dining is generally judged to be safer, but the lack of social distancing, outdoor dining setups that basically recreate indoor structures, and more infectious new COVID variants mean that there are still risks involved with eating out.
The National Restaurant Association, an industry lobbying group that has pushed for the reopening of restaurants even while fighting against raising the minimum wage, took issue with the CDC’s new study, calling the analysis “an ill-informed attack on the industry hardest-hit by the pandemic.” The group’s public statement highlights the caveats that the CDC attached to its analysis, including a lack of controls related to other business closures and the enforcement of local policies, as well as a lack of differentiation between indoor and outdoor dining and whether or not restaurants had adequate ventilation and physical distancing.
While there are some limitations to the study, these general guidelines of “masks = good” and “restaurant dining = some risk” remain critical to keep in mind as states like Mississippi and Texas recently announced that end of mask mandates and the reopening of businesses at full capacity, despite daily new COVID cases still averaging close to 59,000 across the U.S.
“You have decreases in cases and deaths when you wear masks, and you have increases in cases and deaths when you have in-person restaurant dining,” CDC director Rochelle P. Walensky said in a briefing on Friday, per the New York Times. “And so we would advocate for policies, certainly while we’re at this plateau of a high number of cases, that would listen to that public health science.”
As new infections decrease and as more people get vaccinated, guidance will begin to change. According to the CDC’s first set of public health recommendations for vaccinated people, issued today, those who have received the full vaccination dosage can gather indoors with other fully vaccinated people or with unvaccinated, low-risk people from a single household, without masks or physical distancing. But medium- and large-sized gatherings are still not recommended, and fully vaccinated people should still wear masks and maintain distancing in public, when visiting unvaccinated people from multiple households, and when visiting unvaccinated people who are at high risk for severe COVID-19 sickness. Until enough people receive full vaccination, it’s still as important as ever to exercise caution.
- Association of State-Issued Mask Mandates and Allowing On-Premises Restaurant Dining with County-Level COVID-19 Case and Death Growth Rates — United States, March 1–December 31, 2020 [CDC]
- The Virus Spread Where Restaurants Reopened or Mask Mandates Were Absent [NYT]