No, that government-funded mask study doesn’t justify school mask mandates

This is in spite of the fact that the study was knowingly set up in such a way that it would ignore thousands of positive COVID cases in mask-mandatory schools.

The bottom line is that anybody who cites this study as a point in favor of mask mandates is selling you something you shouldn’t buy.

Here are the top four reasons not to read this study as a justification of mask mandates.

1) A vast majority of schoolchildren infected were not infected in school

The researchers found that more than 90% of teachers and students who got COVID got it outside of school. Or, as the authors put it, “Secondary transmission across the cohort was modest (<10% of total infections).”

In mask-optional schools, a higher portion of cases was traced to in-school infection, yet still, a vast majority of all infections in these schools (79%) happened outside of school, according to this study.

Considering that children spend nearly half their waking hours Monday through Friday in school, this finding suggests that schools are very safe — certainly, schools are not less safe than other places. This is why it is indefensible that many states and cities kept their school mask mandates longer than their regular indoor mask mandates.

2) The case reduction the study found was tiny

The media trumpet the study’s finding that mandatory masking correlated with a large percentage reduction in “in-school transmission.”

Every time you see words like “72% reduction,” you need to ask what the absolute numbers are. Only if you know how much in-school transmission there is without masks do you know how significant a 72% reduction is — and how much you should be willing to do to attain it.

Remember, in-school transmission was always modest. The study found that for every 1,000 students in a mask-optional school, about 14 got COVID in school between the beginning of the school year and mid-December (a period that included the delta wave). In the mask-mandatory schools, about seven students got COVID in school in that same period. The average time period studied was 13.5 weeks of school. That means that in an unmasked middle school of 500 students (approximately the U.S. average), two people would catch COVID in school per month, compared to one per month in a mask-mandatory school.

Which is to say, mandatory masking possibly prevented about one COVID case per month in a school of 500.

3) By design and pursuant to CDC guidance, in-school infections went uncounted in mask-mandatory schools

In an attempt to study in-school transmission rather than simply the total number of students and teachers who tested positive, the researchers looked only at “secondary cases” — that is, a COVID-positive student or teacher whose infection was linked, by contact tracing, to another COVID-positive student or teacher at the same school.

This creates a massive problem for comparing masked students to unmasked students, because unmasked students were probably included in contact tracing more than masked students. Why? Because the Centers for Disease Control and Prevention said not to include masked students in contact tracing.

Contact tracing typically involves checking in on close contacts of positive cases. The CDC says that students sitting 5 feet apart count as close contacts if one is unmasked, but if both are masked, they don’t count as close contacts.

So any school or local health authority that followed CDC guidance would be far less likely to connect positive COVID cases in an all-masked class than in a mask-optional class.

Consider this hypothetical:

• In Washington Middle School, which is mask-optional, Joe and Bob sit next to one another, about 5 feet apart. Bob masks, but Joe doesn’t. Joe tests positive for COVID, and then Bob does. The county conducts contact tracing, and, seeing as Bob was a close contact of Joe, counts Joe as a “primary infection” and Bob as a “secondary infection.” Bob, that is, counts as an in-school infection.
• In Adams Middle School, masks are mandatory. The same facts hold, except Jay and Brad both wear masks, and both get sick. The school doesn’t consider Brad a close contact of Jay because both were masked. Thus Jay and Brad both count as “primary infections,” and thus this doesn’t count as an in-school infection.

In such a study, if mask mandates make no difference, you would expect (A) a lot fewer secondary cases detected in mask-mandatory schools because of a lack of contact tracing, and thus (B) a lot more primary cases detected in mask-mandatory schools because nearly all cases would be counted as primary cases thanks to the lack of contact tracing.

Sure enough, that’s exactly what we got, which takes us to point 4 …

4) The study actually found many more COVID cases in mask-mandatory schools.

COVID was more prevalent in mask-mandatory schools in this study than in mask-optional schools.

That’s 136 cases per 1,000 people in mask-mandatory schools compared to 54 cases per 1,000 people in mask-optional schools.

None of this tells me that mandating masks is worth the costs.