Hi W.,
I am not an expert, but I believe they wait until after 2 because they don't recognize autistic behavior until age two or so. Which, coincidentally, the MMR is given around that time. Thus, the controversy begins.
According to my Pedetrician, the MMR has not been linked to Autism. Although, that does not mean it isn't. I asked her what she did with her children and she said she gave them the vaccine. That means a lot to me. She also told me that the ingredient that is supposed to be the aledged cause of autism (mercury or Thimerosal) is no longer in the vaccine. (you need to make sure your dr. does not have old stock)
One other thing, my doctor gave me the choice of giving it separately if I wanted to, which I did. If your doctor won't, and you want it separate, go to another doctor. My doctor is awesome, but she is in Miami Beach (don't know where you are). She never told me it was too costly. I just think your doctor did not have it separate and did not want to order it.
I know my sister-n-law waited until her 2nd son was over 2 before she gave it to him, because her first son had some issues and she was so scared it was the vaccine. But it ended up being speech problems, not autism.
Also, again I am not an expert, from what I understand, Autism is predominantly in males. Yes, there are some females, but mostly males. I believe it is 4-1 ratio (males - females)
Anyway, if you want it given separate, then find a doctor who will do it. You have options and it is your child.
Hope this helps.
If you want my doctors number e-mail me and I'll send it to you.