The science on mask efficacy is settled and has been for a very long time. The vast majority of decades of scientific research regarding the efficacy of masks show they do not prevent the spread of any respiratory illnesses.
A fairly recent study from Denmark involving a sample size of 6,000 participants found that “there was no statistically significant difference between those who wore masks and those who did not when it came to being infected by Covid-19.”
A much larger study led by Yale University found that “Based on the 95 percent confidence intervals, we do not even know if surgical mask efficacy is more than 0 percent.”
Another ecological study of state mask mandates and their use – which included data from the winter case spike – has found that widespread mask-wearing didn’t slow the spread of COVID-19.
The study, conducted by the University of Louisville using data from the Centers for Disease Control and Prevention, found that “80% of US states mandated masks during the COVID-19 pandemic,” but while “mandates induced greater mask compliance, [they] did not predict lower growth rates when community spread was low (minima) or high (maxima).” The study also found that “mask mandates and use are not associated with lower SARS-CoV-2 spread among US states.”
Additionally, the vast majority of gold-standard scientific research compiled over multiple decades, concludes masks are completely ineffective at preventing the spread of respiratory illnesses.
The randomized clinical trial (RCT) is recognized as the most credible research design for clinical investigation. The goal of the RCT is to achieve a valid comparison of the effects of an investigational treatment or treatments with the control treatment (standard of care) in the target patient population. Bias can be reduced by concealing the randomization sequence from the investigators at the time of obtaining consent from potential trial participants.
But now a new peer-reviewed, randomized controlled trial (RCT) of N95 masks shows that they are just as ineffective as surgical masks.
From Just the News:
“Published in the Annals of Internal Medicine (AIM) this week and led by researchers at Canada’s McMaster University, the study found no statistically significant difference in protection between the two kinds of masks in healthcare facilities in Canada, Israel, Pakistan and Egypt.
Funders included the Canadian government and World Health Organization, which unlike the U.S. opposes masking young children and also found “no evidence” face coverings made a difference against influenza in a 2019 study.
Previous RCTs in the COVID era have found mediocre protection from face coverings at best. A Danish study of 6,000 that had trouble getting published — and eventually landed in AIM — found no statistically significant difference between surgical and no-mask wearers.
A much larger Bangladeshi study led by Yale researchers found that villages that got surgical masks reduced symptomatic infection by 11%, but the confidence interval hit zero and statistical significance disappeared for every age group under 50. Cloth masks had an “imprecise zero” effect.”