Watch how face masks in public became the norm as COVID-19 cases spiked

With COVID-19 infections hitting record numbers in the United States this week, the Centers for Disease Control and Prevention has finally decided to get on board with universal mask wearing. Its new guidance, published Friday, recommends “universal face mask use” as a mitigation tactic to reduce transmission of SARS-CoV-2, the virus that causes COVID-19. It comes as colder weather is forcing more people indoors and amid growing fears that cases will spike even higher after large gatherings during the Thanksgiving holiday weekend.

But even though mask wearing has remained a stubborn flashpoint in the culture wars, the adoption of face masks seems to be steadily rising.

That’s according to data from Carnegie Mellon University’s Delphi Research Group, which surveys Facebook users on a daily basis on a number of coronavirus-related topics. One of the questions Delphi asks is whether people wear a mask in public. It then takes those responses to estimate mask adoption within a particular area.

Delphi’s real-time COVID-19 tracking tool—produced in collaboration with health-tech company Change Healthcare—lets you look back at the survey data by each county, or visualize it through a useful color-coded map. Even more useful, you can watch a time-lapse of the visualization by adjusting the map’s display settings to “people wearing masks” and “counties.” From there, click the play button to watch how mask adoption grew from September 8 through this week.

The time-lapse map indicates that, not surprisingly, mask wearing became more commonplace in regions as those regions became more affected by outbreaks. Adoption appears to be especially prevalent in states such as New York that mandated masks early.

Delphi’s tracking tool, called COVIDcast, was launched a while back, but it was recently updated with even more indicators, including de-identified claims data from Change Healthcare. Check out the tool here.