"Religious organizations have sided in favor of vaccines as well, even those generally opposed to abortion. "We should always ask our physician whether the product he proposes for our use has an historical association with abortion," the National Catholic Bioethics Center states on its website, but then goes on to say "one is morally free to use the vaccine regardless of its historical association with abortion." "The reason is that the risk to public health, if one chooses not to vaccinate, outweighs the legitimate concern about the origins of the vaccine," the center's position statement continued. "This is especially important for parents, who have a moral obligation to protect the life and health of their children and those around them." Offit said he was glad the Catholic Church supports vaccination. He noted it is particularly ironic to object to the rubella vaccine using fetal cells because Cardinal Joseph Ratzinger, who later became Pope Benedict XVI, commented on the subject in 2003, saying: "Universal vaccination has resulted in a considerable fall in the incidence of congenital rubella, with a general incidence reduced to less than 5 cases per 100,000 livebirths." In other words, Offit explained, the rubella virus increases the risk of spontaneous abortion. In the U.S., vaccination prevents up to 5,000 miscarriages each year in the U.S. alone, he said."