Chicago Tribune file.

No proven benefit

Panicked governors and school boards are rushing ahead with “mandates” requiring students to wear masks. Sadly, the assumed benefits are not supported by science.

A recent, lengthy and solidly reported story in New York magazine’s Intelligencer by  DavidZweig concludes that, “The science of masking kids at school remains uncertain.”

At the end of May, the Centers for Disease Control and Prevention published a notable, yet mostly ignored, large-scale study of COVID transmission in American schools. A few major news outlets covered its release by briefly reiterating the study’s summary: that masking then-unvaccinated teachers and improving ventilation with more fresh air were associated with a lower incidence of the virus in schools. Those are common-sense measures, and the fact that they seem to work is reassuring but not surprising.

Other findings of equal importance in the study, however, were absent from the summary and not widely reported. These findings cast doubt on the impact of many of the most common mitigation measures in American schools. Distancing, hybrid models, classroom barriers, HEPA filters, and, most notably, requiring student masking were each found to not have a statistically significant benefit. In other words, these measures could not be said to be effective.

In the realm of science and public-health policy outside the U.S., the implications of these particular findings are not exactly controversial. Many of America’s peer nations around the world — including the U.K., Ireland, all of Scandinavia, France, the Netherlands, Switzerland, and Italy — have exempted kids, with varying age cutoffs…

These countries, along with the World Health Organization, whose child-masking guidance differs substantially from the CDC’s recommendations, have explicitly recognized that the decision to mask students carries with it potential academic and social harms for children and may lack a clear benefit. To date, the highly transmissible Delta variant has not led them to change this calculus….

The study published by the CDC was both ambitious and groundbreaking. It covered more than 90,000 elementary-school students in 169 Georgia schools from November 16 to December 11 and was, according to the CDC, the first of its kind to compare COVID-19 incidence in schools with certain mitigation measures in place to other schools without those measures. Scientists I spoke with believe that the decision not to include the null effects of a student masking requirement (and distancing, hybrid models, etc.) in the summary amounted to “file drawering” these findings, a term researchers use for the practice of burying studies that don’t produce statistically significant results.  [My emphasis.]

There’s no comparable, robust study, according to Zweig. He notes that “The closest is a study published in Science, based on a Facebook survey, that was suggestive but not conclusive of a marginal benefit of student masking,”

How to say this so that the anti-science partisans understand it?: No persuasive study shows there’s a benefit to young adults masking in school.

Doesn’t matter. I will be instructed by the blindly partisan that “science” says otherwise. Another sad and threadbare appeal to supposed authority.