FACE MASKS: ARE THEY LESS EFFECTIVE THAN THEY WERE?
As various illnesses circulate, calls for face coverings are once again being heard. Are they still a good way to reduce risk of COVID?
With fresh concerns over rising flu, Strep A and COVID XBB.1.5 cases, health officials across the UK are scratching their heads over one key question: should we all be wearing masks again?
While the UK Health Security Agency has advised adults who are displaying flu or COVID symptoms to wear a face covering, some public figures, such as Scottish First Minister Nicola Sturgeon, have advised all healthy adults to wear a mask in certain settings.
But as COVID begins to stabilise in the UK, some scientists have questioned how effective face masks are at controlling current case numbers.
“Masks were really helpful early in the pandemic,” says Prof Paul Hunter from the Norwich Medical School of the University of East Anglia. “But there is evidence that masks were an essential part of our control measures up until the point that we’d effectively vaccinated as many people as we were going to. What we’ve seen this year is that their protection has evaporated.”
This claim hinges on data collected by the Office of National Statistics (ONS) between November 2021 and May 2022 that monitored how likely people who did and didn’t wear a mask were to test positive for COVID. The figures indicate that towards the end of 2021, children and adults who said they ‘always’ wore a mask at work or school were less likely to test positive for COVID-19 than those who ‘never’ or ‘sometimes’ wore a mask.
From January to May 2022, however, the likelihood for both groups to test positive was extremely similar.
But some scientists have said there isn’t enough data to draw a solid conclusion, highlighting how the ONS figures were last collected in May 2022 – eight months ago. “You can draw a general conclusion from these data. But I think an informed conclusion would be unwise because of the complexity of the situation. The virus has changed substantially over
that period,” says Hugh Pennington, emeritus professor of bacteriology at the University of Aberdeen’s School of Medicine, Medical Sciences and Nutrition.
According to Hunter, while mask-wearing and school closures had a big impact at the start of the pandemic, their effect has lessened as we approach ‘endemic equilibrium’ (where case numbers remain at a relatively low and constant level, with most people having had COVID at least once and having received at least one vaccination). “As more people get the infection and recover, the risk changes. Many of the people you may infect are actually immune, so they don’t actually get infected,” Hunter says.
There’s been another big change since the pandemic started: the SARS-CoV-2 virus itself. “Omicron is so infectious that it’ll spread no matter what we do,” says Hunter.
Some research has also demonstrated that masks may only delay infections, a conclusion reached in a US study that compared schools with and without mask mandates across 1,832 counties. Initially, schools with mask mandates were less likely to seek care for COVID, but the difference in numbers between the two groups disappeared in a few weeks.
Hunter says: “I think – and this is a theory – that children who have never worn masks in schools are more likely to have had an infection earlier on. So by now, they’re more likely to be a lot more immune than children who have always worn masks. At this point, the extra immunity balances out reduced exposure.
“And if you’ve been religiously wearing a mask, you’re less likely to have had COVID. You’re less likely to have what’s called hybrid immunity – immunity from a previous infection and vaccine. That’s the best immunity you can have.”
While he views infection as largely inevitable, Hunter does recommend that some groups should still wear a mask in public. “If I was much older or had a health condition that put me at risk, I would continue to wear a mask,” he says.
Other scientists argue that all adults should wear masks in certain settings to protect themselves and others. “I think the public health advice has to be in favour of masks,” says Prof Christopher Dye, epidemiologist and public health expert at the University of Oxford. “You really don’t want to get infected, so you can protect yourself from future infections. Even now, it’s not a good idea to get COVID. There’s no real need to wear a mask in an open high street, but in enclosed, high-risk settings, it’s simply sensible.”
“There’s no real need to wear a mask in an open high street, but in enclosed, high-risk settings, it’s simply sensible”