Both my kids got the "flu" going around. It lays out vaxed kids for 5ish days. For my unvaxed kids, it was a 24-hour bug.

thank you for not vaccinating your children!

Would viruses mutate and become weaker when going through a population with reduced immunity? They don't want to kill their host, and if the host has a limited immune system, they would have to evolve to become weaker so not to kill the host.