My vote is that if you are concerned, there is a reason for your hesitation, trust your instinct, don't do it. I stopped vaccinating both of my kids before the MMR shot (this is the one that is speculatated to trigger Autism, it is a combination of 3 vaccines in one). I feel strongly that there is a link between pharmeceuticals, in general, that we put in our body correlated to the growing percentages of disease. But the main reason I did not have my kids vaccinated is that my husband is adopted, and genetically speaking, I have no idea what my kids are predisposed to. God forbid either of my children develop Autism, I wouldn't know with 100% certainty that is wasn't because of a vaccination they had. Personally, I couldn't live with knowing that, so I took it out of the equation.
There was a really great episode of Oprah with Jenny McCarthy & Holly Robinson-Peete, that speaks to Autism and vaccinations, you may be able to find it on You Tube. Jenny Stated that she didn't know that it was the shot itself that caused her son to have Autism, rather something in his genetic makeup that when combined with the vaccination caused a change.
Many doctors are quick to push vaccines, it is a science they dedicate their lives to, but you are lucky to have one that doesn't guilt you into it. And to quote McCarthy again, "My son is my science," meaning that, as a mom, we know our kids explicitly, better than anyone. SO trust your instinct.
You can always opt to have the vaccine later, when he is older than 2, (many moms of kids with autism say that on the eve after the shot was given, their child spiked a fever and by the next morning, symptons occurred, including loss of vocabulary). Or, contact your insurance company, they may cover having each of the 3 components administered individually.
But I think you are on the right track by wanting to wait or omit altogether. Every body is different and can tolerate different types of things. Vaccinations are 'one size fits all,' and it really is a gamble.
Good luck with your decision,
G.