Earlier quoted context omitted.
A tiny fraction of infants react to infant vaccinations. But the harm those children experience is a infintesimal fraction of the harm all children would feel if there were no infant vaccinations. It's a trade off but it's one that must be made. The parents whose child died did the best thing they could do. Until we can screen for the infants that will react, vaccinations are the best choice.
They did the best for society, not for their child. Yes, vaccines are the best choice, there is no doubt about that. But the society in question must take much better care of those who sacrifice so much for the whole.
Herd immunity arguments can make that calculation more fuzzy but the herd can't tolerate many people opting out and still give group cover. So after a certain amount of people, choosing not to vaccinate is seriously risking illness. Society is built to handle those types of collective action problems. The moral case is still clear IMO.