According to an analysis from the “gold standard” of evidence-based reviews, wearing medical/surgical masks or N95/P2 respirators to stave off the transmission of respiratory viruses may be largely ineffective.
The Cochrane Institute updated its review from 2020, examining 78 global studies comprised of more than a million people. They found that wearing a mask in a community reduced the risk of getting flu or COVID-like illness by a paltry 5%, according to The Daily Mail.
“Irrespective of the limitations of the study, its results indicate that the true impact of medical/surgical masks and N95/P2 respirators on the transmission of respiratory viruses is at best small,” Professor Francois Balloux, professor of computational biology at University College London, reacted.
But Eberhard Bodenschatz, professor of Physics and director at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, countered, “The Cochrane study is not very meaningful. … Our studies have clearly shown that masks are physically wonderful protection.”
Bodenschatz slammed the authors of the study, saying, “In one sentence they write that masks don’t work, and a paragraph later they admit that they can’t really say it.”
The researchers conducted six trials during the COVID pandemic; two from Mexico, and one each from Denmark, Bangladesh, England, and Norway.
“We included 12 trials (10 cluster‐RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and 10 in the community),” the researchers wrote. “Wearing masks in the community probably makes little or no difference to the outcome of influenza‐like illness (ILI)/COVID‐19 like illness compared to not wearing masks.”
“The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions,” the researchers admitted, adding, “We are uncertain whether wearing masks or N95/P2 respirators helps to slow the spread of respiratory viruses based on the studies we assessed.”
The researchers posited that the possible lack of effect of masks could be attributed to many reasons, including, “poor study design; insufficiently powered studies arising from low viral circulation in some studies; lower adherence with mask wearing, especially amongst children; quality of the masks used; self‐contamination of the mask by hands; lack of protection from eye exposure from respiratory droplets (allowing a route of entry of respiratory viruses into the nose via the lacrimal duct); saturation of masks with saliva from extended use (promoting virus survival in proteinaceous material); and possible risk compensation behavior leading to an exaggerated sense of security.”