Depends if you travel a lot with your baby. Also, it would be safer to take the injection before your BB goes to school. As my son attend playgroup and we travel with him a lot, so he took the injections lor...
Your son is over one year old?? If so, only need two injections. Over 2 years old, only 1 injection. Each one is about $650 and my son had no side effect at all. I hope it answer your question.