I've read speculation that chickenpox is a seasonal disease, and that one difference between severe cases and mild cases is the child's vitamin D level. It is

I've read speculation that chickenpox is a seasonal disease, and that one difference between severe cases and mild cases is the child's vitamin D level. It is unfortunate that children are now commonly vaccinated against chickenpox. This is a weakling virus that barely kills anyone, and more good could be done by figuring out factors that help children have a mild case.