You'll drive yourself crazy focusing on every minor risk for children. COVID risk for unvaxed kids is the same as fully vaxed 40 years and much lower than fully vaxed seniors.

If you want to do some productive worrying, figure out how to reduce your child's risk of dying in a car crash. That's much more of a risk.

>Moderna was supposed to close out a trial in late November but instead expanded it to hundreds of new participants. Why? Unclear.

If I had to guess it is probably because you need a large group to prove its effective since so few children get seriously ill. Child mortality is under 0.0002%. You need a huge control group to get any sense of whether the vaccine works at preventing deaths.