A new study in JHI uses a pragmatic time series analysis to provide some data to suggest that stopping a universal mask mandate at St. George’s Hospital in London did not result in an increase in healthcare-associated SARS-CoV-2. The authors were careful to point out that the findings do not show that “masks don’t work”, but rather that in this setting, at this time of the pandemic, removing a universal masking mandate didn’t result in a detectable increase in the rate of healthcare-associated SARS-CoV-2.