Regarding transmission in children, I might be ponied here as this is a few weeks old, but the gold standard now is an Iceland study, in fact check out National Geographic’s headline:
The study found that children (defined by them as 15 and younger) transmit the virus half as effectively as adults. The study was very well controlled:
The best way to understand how transmission might occur between children and adults would be to constantly monitor healthy families with school-age children to see if they get infected. By testing frequently, scientists would catch infections as they occur, making it clear who got sick first.
Iceland and deCODE put this into practice by conducting comprehensive testing and tracing, screening more than half the country’s population: Anyone who was potentially exposed was quarantined, sealing them off from the community, but often exposing their families. By looking at the difference between adults and children in these quarantines, deCODE found that children play a minor role in transmission.
This is as close as you’re going to get to a lab-conditions study. This joins other large studies from South Korea and Germany, as well as many other smaller studies, in concluding that children are much less efficient transmission vectors than adults. The Princeton study from September which Dan has linked several times now is the only large study I’m aware of to come to the conclusion that children spread as efficiently as adults, and has a few limitations, a couple of the major ones are:
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Their definition of “children” goes up to 17 years. There’s no disagreement that older teenagers spread just as efficiently as adults, in fact 15 in the Iceland study is older than I’d like. (There’s discussion of this and links to many other studies in the section “Don’t treat all ages the same” in the NatGeo article).
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The study took place in India, where conditions are very different in terms of high-density living, inadequate hygiene and so forth. It’s possible children do transmit just as effectively under these conditions, although I’m still skeptical given the weight of other data we have.
The author of the study goes on to say:
Iceland never closed its elementary schools, although it did close its high schools at the peak of its first surge. Data from its wave in September support the idea that younger children are less likely to get sick or to infect others. Stefánsson is in the process of publishing these results in a peer-reviewed journal, but he says the meticulous dataset is conclusive for Icelandic transmission—“and we have turned out to be a reasonable animal model for the human population.”
Stefánsson cautions that if everything but schools and childcare centers are closed, children would then become one of the primary sources of transmission. He explains that while the individual risk might be low among youths, schools will still have outbreaks.
That means the question becomes not a scientific one, but rather what level of risk society is prepared to accept to keep children in school: “What are you willing to live with?” he asks.
This is sort of the opposite of what school-closure advocates are saying, that schools should be closed when trying to get an outbreak under control. The state of Victoria here closed schools during their outbreak but:
Brett Sutton, Victoria’s Chief Health Officer also said that in retrospect, the state would not have closed schools. Partly thanks to his advice, Ireland left its schools open during the most recent lockdown while closing gyms, churches, restaurants, and non-essential businesses. Nevertheless, community infections have declined by 80 percent in six weeks.
“Our priority to keep the virus out of schools,” Russell says, “is to keep it out of the community.”
That last sentence is my opinion in a nutshell. I recommend reading the whole NatGeo article, it’s a good summary.
