You are the problem, and you should feel bad. Unless there is an explicit medical reason why (your child is legitimately allergic to the contents of the vaccine) there is no good reason to not vaccinate your child immediately. You are in the same crowd as the anti-vaxxers, because you're afraid of some 1 in 14000 boogeyman. Do you not drive your car because you're very likely to be seriously injured in the process of doing it? Your idea of waiting until they were older is absolutely just as ridiculous.
Just to clarify, you should never hold someone having a seizure. You should clear out things they could hurt themselves with, but never hold them. I see clearly that smart decisions runs in your entire family. I seriously hope you didn't hurt your children's health by getting them vaccinated later in life.