More data: Just 0.4% of students infected in L.A. school district over five weeks of summer school

AP Photo/Denis Poroy

A follow-up to last night’s post about the rich abundance of anecdotes and paucity of hard data we have about kids doing worse with Delta. Plenty of doctors treating sick children right now will tell you, observationally, that Delta is worse. “I do think we’re seeing more severe disease and I think part of that is because the kids we’re seeing don’t have underlying medical conditions,” said one Florida pediatrician to Axios. That’s alarming, but if Delta really is harder on kids such that it’s worth rethinking how we plan to proceed in schools, we should be able to quantify it. Are a greater percentage of children getting very ill relative to how they fared with previous strains?

Don’t be so sure. The same Axios piece quotes another pediatrician in Washington as saying, “It’s really remarkable. The entire time, it’s been the exact same percentage who’ve been hospitalized and the exact same percentage who’ve been critically ill. We’ve not seen a change even though the type or variant of virus has changed.” Hmmmm. As for transmissibility, yesterday I flagged these numbers from New York City’s testing in public schools over the past month:

The L.A. Unified School District has also been testing students who participated in its summer-school program from the end of June through mid-July. With 44,000 kids attending, they saw a grand total of 174 infections. Just 0.4 percent.

And only 12 of those infections — 0.03 percent — happened in school, as best they can tell.

By the time summer school ended, L.A. County’s positivity rate among the general population was 4.2 percent, much higher than the rate among kids attending class. Even in the age of Delta, it seems, a surprising truth from last year abides: Kids appear to be safer from COVID in school than they are outside of it.

So why would we keep them home this fall?

Two caveats apply to the numbers above. One is that Delta had only just begun to accelerate in California in late June, when summer classes began. As you can see from the week-by-week numbers, as the variant spread throughout the state, more kids began getting infected. (Although there was no spike in infections on school grounds.) In less than a month, confirmed cases among students tripled; there’s potential for mini-waves of Delta to sweep through schools in the fall. Even so, says the LA Times, “Officials found no cause for alarm regarding the summer school infections” and continue to believe that “a classroom remains the best place for the vast majority of students for the coming school year.”

The other caveat is that LAUSD is taking plenty of precautions to try to limit transmission. They upgraded their ventilation systems, they test regularly, and they mandate masks for kids — even outdoors. Would there have been more infections in summer school there this year if kids weren’t masked up? No way to know. We’ll have to wait for data this fall from states like Florida, where some counties will require masks on students (in defiance of Ron DeSantis’s ban) while others won’t.

The most important metric is kids becoming seriously ill, though. If Delta is leading to more of that then in-person schooling becomes riskier. The best evidence we have at the moment, per economist Emily Oster, is that Delta isn’t different in that regard from previous strains:

I would argue, though, that what we do know suggests the risks are in the same range. That the narrative that this is a new virus which is tremendously more dangerous for children is just simply not supported by the data.

For example: In the data from the UK, the risks of hospitalization are similar for children during the Delta wave as during previous ones. And the AAP data shows fairly consistent hospitalization rates over time. Finally, we aren’t seeing a significant increase in the number of pediatric hospitalizations in areas with high vaccination rates for adults, which is also encouraging.

It could be that Delta is moderately more serious for children, but it is not clear. We need more data for this to be precise. I hope the CDC is collecting it, quickly.

Note the bit about pediatric hospitalizations being lower in areas where a greater share of adults are vaccinated. That jibes with data from Israel showing that kids who live around vaccinated adults are less likely to get infected than kids who live around unvaccinated elders, for the logical reason that there are fewer vectors of transmission in the first group. Why the White House hasn’t hammered that message as a way to persuade adult vaccine holdouts to get their shots, I can’t understand. The best way to keep your kids safe from Delta (until they’re eligible themselves) is to get vaccinated.

According to Oster’s analysis of available data, kids under 18 have roughly the same risk of hospitalization from COVID (one in 200) as they do from the flu (one in 240), although that’s obviously subject to revision as more kids come into contact with Delta this fall. (It also doesn’t account for the fact that most kids under 18 aren’t eligible for the COVID vaccine yet.) Given the encouraging summer-school data from New York and L.A., though, plus the mounting evidence that keeping kids out of class may be damaging them irreparably, there’s no question that the school year should begin with everyone back full-time. If Delta turns out to be worse than we feared, we’ll have to adjust. But the almost unshakeable default position on in-class instruction should be full speed ahead, with a strong warning to parents that their refusal to get vaccinated is more of a risk to their kid than sending them back to class is.

I’ll leave you with Scott Gottlieb lobbying yesterday for governors to let local school officials decide whether kids should be masking or not in accordance with the threat level in their community.