Hi Jennifer,
I feel like a broken record of late -- I have posted this same reponse twice already in the past two weeks. (See my posting to Sepi B on 1/14 -- you don't need to read the same article twice!)
There is NO scientifically established causal link between autism and the MMR vaccine. The potential for death/lifelong disability caused by these diseases (for both the child and pregnant women an infected child might come in contact with) are far more likely to occur than the incidence of a negative reaction. Get the vaccination, and get it on schedule.
The chicken pox vaccine is a different story. The rate of severe consequences from Herpes zoster is very low, although it does carry with it risks to women who deliver with an active infection, to anyone if pustules develop in the eyes, and later in life if it reappears as Shingles (a very painful and sometimes, but rarely, debilitating disease). Because it is more of a nuisance than a danger, I chose to delay vaccinating my daughter until after first grade. My reasoning was that the disease grants life-long immunity in most cases, but the vaccine does not. I preferred to have her not miss 1 - 2 weeks of school if she came down with chicken pox, however, so I decided to wait on the vaccine, hoping that she would get the disease and get it over with before it would get in the way of school.
BTW, both my husband and I had chicken pox as adults. It was one of the WORST experiences of my life! I was very sick for a month and had residual pain along one of the nerve trunks (in which the virus went dormant) for over six months.
Best regards,
R.