Evidence shows face masks do work against respiratory viruses
Kate Atkinson
November 18, 2024
WHAT WAS CLAIMED
No study has ever proven face masks protect against viruses.
OUR VERDICT
False. Numerous studies have shown face masks are effective against viruses.
AAP FACTCHECK – A false claim that there’s no evidence to show face masks protect against the spread of viruses is being shared again almost five years since COVID-19 was first detected.
Numerous studies find face masks are effective in protecting against viruses and respiratory infections.
The claim appears in an October 29 Facebook video posted by New Zealand anti-vaccination activist and preacher Billy Te Kahika.
“There’s never been a study on face masks that prove that they protect you from viruses … Why are they bringing in … mask mandates … [if they know that the] masks themselves don’t work,” he says (49 minutes 38 seconds).
Abrar Chughtai, a medical epidemiologist at UNSW, told AAP FactCheck there is “ample evidence” supporting mask use.
“Masks are, if correctly and consistently worn, effective in reducing transmission of respiratory disease,” he said.
David Fisman, a professor of epidemiology at the University of Toronto, agreed “there’s a mountain of both mechanistic and epidemiological evidence to suggest this assertion is nonsense”.
Dr Chughtai pointed to a meta-analysis he co-authored that analysed more than 100 reviews and studies on mask wearing, published in May 2024.
It found that “masks are effective … in reducing transmission of respiratory pathogens” (page 46).
It also found that mask mandates were effective in reducing transmission during periods of high community transmission (page 46).
Respirators, for example N95 masks, are significantly more effective than medical or cloth masks, Dr Chughtai added.
In 2023 a review published by the Cochrane Library was widely misinterpreted as proof masks are ineffective against viruses, despite its “uncertain” findings.
Multiple other studies have shown masks offer protection from viruses.
A 2009 Australian study investigated how well P2 respirators and surgical masks worked in households where a child had demonstrated respiratory illness symptoms.
The researchers did not enforce mask-wearing on the adult study subjects, and fewer than 50 per cent of people wore masks most of the time (p233).
However, an adjusted analysis of participants who did adhere to mask wearing found they reduced the risk of developing a respiratory infection by 60 to 80 per cent (p238).
A 2020 study on the transmission of COVID within families and close contacts in Beijing also found masks offer protection.
It determined that mask use by an individual with COVID and their family contacts before the positive case developed symptoms was 79 per cent effective in reducing transmission (page 1). (AAP)
