There is little or no evidence that children frequently transmit the virus to adults. And even if there was, it wouldn't be ethical to collectively punish all children just to marginally reduce the risk to a minority of vulnerable people.
> Researchers in South Korea have found that children between the ages of 10 and 19 can transmit Covid-19 within a household just as much as adults, according to new research published in the US Centers for Disease Control and Prevention journal Emerging Infectious Diseases