"In 1964, the Wistar Institute developed the RA 27/3 strain of rubella virus. The rubella virus isolate “was recovered from the explanted [kidney] tissue of a fetus obtained at therapeutic abortion from a mother who had been infected with rubella virus”. The scientific literature of that era indicates that the abortion was not conducted with the motive of isolating the virus, but rather because the mother was infected with rubella virus and risked major birth defects. After the RA 27/3 strain was isolated, it has been propagated serially in human diploid cells. The RA 27/3 strain produced superior antibody responses and was better tolerated, compared with other rubella vaccine strains available in the 1960s. No further abortions are necessary to sustain the manufacture of additional batches of rubella RA 27/3-strain vaccine. Use of the RA 27/3 rubella virus strain was also considered by the National Catholic Bioethics Center and the Pontifical Academy for Life. Using the same logic, they reasoned that because the one abortion that yielded the viral isolate was not undertaken with the intent to retrieve the virus and because no additional abortions are needed to obtain more virus, being immunized is morally acceptable and also associated with parental duty. The same provisions for preferring alternatives and petitioning governments and manufacturers also apply. Some find it meaningful that rubella vaccination prevents many cases of fetal death and congenital rubella syndrome that would otherwise occur if women were infected with rubella virus during pregnancy. Immunized women exposed to the virus during pregnancy are no longer confronted with the question (what some religions might consider temptation) of whether to terminate their pregnancies on that basis."