I think the comments you read about on this site are already as people who
did not have any issue after the vaccination are less likely to initiate a
post to talk about "no reaction".
My son took his shot at age 1 together with chicken pox and the first shot
of flu shot, no reaction; but I'm not going to tell you that you shouldn't
worry just because we didn't experience any issue. You are the mother, you
have to make educated decision for your child. I just want to tell you that
we are at least 1 case that didn't have a problem.