What Aborted Fetuses Have to Do With Vaccines

A small but growing number of parents who object to vaccinating their children on religious grounds say they do so because many common vaccines are the product of cells that once belonged to aborted fetuses.

There is a grain of truth to this statement. But even religious leaders, including a future pope, have said that shouldn't deter parents from vaccinating their children.
http://abcnews.go.com/Health/aborted-fetuses-vaccines/story?id=29005539&google_editors_picks=true