You can't actually answer those interrogations without a scientific background. You're not doing "research on", you're probably reading articles written by uninformed people, though obviously most of these people spreading fear are honest, but some of them have an agenda and sell their BS therapies. Vaccines is one of the main factors of increasing human life expectation, and not vaccinating your child puts him and other children around him at risk of horrible diseases, which is an avoidable tragedy. Please trust "real" doctors on this issue rather than the countless internet "information about vaccines" websites...