We were infuriated when a few weeks ago the Wall Street Journal published a long Weekend Review article claiming that masks were an effective way to stop the spread. That conclusion runs contrary to most of the evidence.

Here’s an important new study that, as far as we know, no US hospital bothered to do. St. George’s Hospital in The UK ended its mask mandate for staff and visitors for some – but not all – wards and compared the outcomes for hospital-acquired COVID infections before and after the mandate was lifted in both the intervention and control groups.

The study says: “Utilising a robust quasi-experimental approach, we found no evidence that a mask policy significantly impacts the rate of nosocomial SARS-CoV-2 infection with the Omicron variant.  While these data do not preclude a small effect, the real-world benefit of this mitigation measure in isolation is likely to be modest within a healthcare setting.”