This is an interesting question.
I initially disliked vaccines because of possible serious reactions - rare, I know, but pinning down how rare is tricky. In most cases it seems the possibility of a serious vax reaction is higher than the possibility of getting the disease and having a serious reaction.
It is, however, more than that. At the end of the day I do not choose invasive preventative health measure unless there is a true risk.
Example - I do not cut off foreskin on the off chance they might develop an issue with their penis, I do not remove tonsils (something routinely done in my parents generation) in case they might develop issues, I am unlikely to put someone on a round of preventative antibiotics unless there was a darn good reason. I declined goop in the eyes at birth. Injecting a healthy person with a substance goes against what I believe.
I think it would be very hard for me to trust the vaccination process to the point where I would ever consider vaxxing. My DD brought a Gardasil sheet home for signature the other day. While it listed some risks, it really glossed over serious side effects. There is also serious under-reporting of side vaccine side effects to watchdog organisations. There isn't a month that goes by on MDC without a post on "my baby had a bad reaction, I called the doctor, and they did not take me seriously." Trust is a hard thing to win back.
While I would not have said so while they were younger, I am increasingly feeling that vaccines are my childrens decisions. If they want to inject their bodies with stuff once they hit adulthood - it is their bodies. I am not going to do it on my watch.
This is my long winded way of saying "both."