"This winter season, the New York Times, Washington Post, Wall Street Journal and Atlantic, among other outlets, have all published articles on the same theme. According to their advice, we should re-don masks to prevent seasonal spread of influenza, RSV, Covid-19 and run-of-the-mill colds. This seems poised to become a yearly occurrence, as with the accompanying post-holiday mandates in some schools, colleges, and elsewhere that these articles actively encourage.
However, while these articles are full of quotations from health officials and disease experts, glaringly absent is high-quality data to support claims that masking reduces spread of circulating seasonal viruses.
The reason for this omission may be that, three years into the pandemic, there are no rigorous studies showing masks to be an effective method of viral infection control. In fact the highest-quality scientific studies, randomised controlled trials (RCTs), show the opposite: that masks make little to no difference in controlling spread of influenza, SARS-CoV-2, or RSV.
In May 2020, the CDC summarised data from 14 RCTs as failing to show a significant benefit of masks in reducing transmission of influenza. An analysis of nine trials conducted by Cochrane, an organisation that conducts large reviews of health-care interventions, reached similar conclusions in November 2020. Studies of masking to prevent common colds and RSV also had negative results.
For Covid-19, there are two RCTs evaluating masks’ ability to cut viral spread. One, conducted in Denmark in the spring of 2020, found no statistically significant difference in infection rates between masked and unmasked groups. Another, bigger, RCT — conducted in Bangladesh from late 2020 until the following spring — showed a small but statistically significant reduction of symptomatic Covid-19 cases in villages using surgical masks. Yet even this small benefit was lost upon reanalysis using different statistical parameters. An additional finding that mask colour made a difference in effectiveness further suggests that this positive data were skewed in some way.
Another rigorous study, though not an RCT, was conducted in schools in Catalonia, Spain. This showed that unmasked five-year-olds had similar Covid-19 case rates to masked six-year-olds, the age at which masking was mandated. "
The scientific case against face masks - The Post (unherd.com)
