There are a lot of different opinions around immunizations and whether to give them or not. This is a pretty touchy subject with some people.
I did a fair amount of researchand decided not to give my baby his Hep B shot in the hospital. It's one that has caused questions as to whether it caused problems, and we are not in an area where we are at risk, so he'll have it in a while. I will also wait for the MMR (measles, mumps and rubella) until he's a bit older and when I do have him immunized for them I plan to ask for them to be without mercury.
Some of the shots you shouldn't wait on. Ask your baby's doc what they recommend. I am lucky to have found one who agrees with me and respects my decision to hold off on some.