A team of researchers from Monash University in Australia and the University of Edinburgh looked at the findings of more than 30 studies from around the world and concluded that mask wearing led to a 53% reduction in the incidence of Covid, while social distancing measures led to a 25% reduction.
Writing in the BMJ, the study authors said: “This systematic review and meta analysis suggests that several personal protective and social measures, including handwashing, mask wearing, and physical distancing are associated with reductions in the incidence of Covid-19.”
The findings confirmed the importance of a suite of public health measures alongside robust vaccination programmes, the researchers said, with mask wearing the most impactful.
Washing your hands was also shown to lead to a 53% reduction in Covid incidence, but given the smaller number of hand-washing studies in the analysis, researchers said it couldn’t be deemed statistically as significant.
Policy measures such as lockdowns, and closures of borders, schools and workplaces needed further analysis to weigh up their positive and negative impact, the authors added.
Rules on mask-wearing vary from country to country around the world – and even within the UK.
Wearing a mask or face covering is not currently compulsory in England, though it is still mandated in most indoor public spaces in Scotland, Wales and Northern Ireland. Rules on masks and coverings were lifted in July in England along with most other remaining lockdown restrictions.
Since then, levels of mask wearing has steadily decreased. According to the Office for National Statistics, the percentage of people in England, Scotland and Wales who said they had worn a face-covering outside their home in the past week dropped by 9% between July 28 and October 3.
While not mandatory, the current mask guidance for England states: “You are expected and recommended to continue wearing a face covering in crowded and enclosed spaces where you come into contact with people you don’t usually meet. In particular, where the risk of transmission is likely to be greater.”
Health secretary Sajid Javid, speaking in the House of Commons in October, said there could be a reintroduction of Covid restrictions in England if “people don’t wear masks when they really should”.
The government faced criticism for this messaging, given many MPs weren’t wearing a mask as Javid spoke.
Boris Johnson has since been criticised for not wearing a mask during the G20 summit in Glasgow and during a hospital visit – mask wearing is still mandated in NHS settings. The prime minister has since apologised.
Trisha Greenhalgh, professor of primary care health sciences at the University of Oxford, previously stressed to HuffPost that the pandemic is ongoing and we should be protecting ourselves accordingly – including by wearing a mask.
“The effectiveness of masks depends on several things: the filtration properties, the fit (any gaps round the sides for example), and whether you’re actually wearing it all the time,” she advised.
While masks and coverings primarily protect other people from the transmission of Covid particles, research also shows they boost protection for the wearer.