I know, that is my point. Parenting is a juggling of risks.
"based on the information available"
And the information avaiable is confusing and partly contradictory.
I know that many researchers advised against child vaccination, because of the unknowns and the low risk for the children from the disease in the first place.
"Making them work at all takes a huge level of understanding."
It does, but it would be news to me, that the immune system is completely understood. Even less the immune system and long term effects of a immune system that is developing.
It was cutting edge research and to my understanding it was more of: this might work.
And it did and unlike the anti vaxx crowd told us, apparently we did not die from it, nor were there mass severe long term damages to be found. But there was damage, some likely did in fact die from the vaccines and so it is not a 100% clear obvious decision. It might have been for you, that is allright and it was allright for me, but for my infant children I did not feel like making that experiment.