VATICAN CITY -
The Vatican has hardened its opposition to using embryos for stem cell research, cloning and in-vitro fertilization.
But in a major new document on bioethics, it shows flexibility on some forms of gene therapy and using vaccines prepared with cell lines derived from aborted fetuses.
"The Dignity of a Person" document issued by the Vatican's Congregation for the Doctrine of the Faith, also criticized "embryo adoption," whereby infertile couples adopt embryos frozen during in vitro techniques and subsequently abandoned.
It said that while the intent is "praiseworthy" the result poses legal, medical and psychological problems.
The Vatican's overall position is informed by its belief that human life begins at conception and must be given the consequent respect and dignity from that moment on.
The Vatican also holds that human life should be created through intercourse between husband and wife, not in a petri dish.
As a result, the Vatican said it opposed in vitro fertilization because it involves separating conception from the "conjugal act" and often results in the destruction of embryos.
It similarly opposed the techniques involved in IVF -- selective reduction of embryos, pre-implantation diagnosis and embryo freezing -- because embryos are or can be destroyed.
It also said it opposed the morning-after pill, even if it doesn't cause an abortion, because an abortion was intended. That could complicate the situation of some Catholic hospitals in the United States that offer the morning-after pill to rape victims.
In the use of drugs such as RU-486, which causes the elimination of the embryo once it is implanted, the "sin of abortion" is committed, the document said, thus their use is "gravely immoral."
The Vatican spokesman, Rev. Federico Lombardi, agreed that, on a superficial reading, the document could be seen as a litany of "no's."
"But it's not like that. It is based -- starting with its title -- on the fundamental affirmation of the dignity of the human person," he said.
The Vatican did show flexibility in saying that parents could in good conscience use vaccines for their children that were developed using cell lines from an "illicit origin."
Religious groups in the United States have pressed the Vatican to issue a statement concerning the morality of using vaccines developed using cell lines derived from aborted fetuses.
"Grave reasons may be morally proportionate to justify the use of such biological material," the instruction said, adding that the parents would have to make known their disagreement with the way the vaccines were developed and press for alternatives.
But the document was strong in stressing that researchers using such material had a greater degree of responsibility. It said they had a moral duty to remove themselves from the "evil aspects" of the original, illicit act -- even if they and their institutions had nothing to do with it.
The document said gene therapy on regular cells in the body other than reproductive ones was in principle morally licit since it sought to "restore the normal genetic configuration of the patient or to counter damage caused by genetic anomalies."
But it said cell therapy that seeks to correct genetic defects with the aim of transmitting the therapy to offspring was more problematic. It didn't rule it out, however.
"Because the risks connected to any genetic manipulation are considerable and as yet not fully controllable, in the present state of research, it is not morally permissible to act in a way that may cause harm to the resulting progeny," the document said.
In the instruction, the Vatican repeated that it fully supported research involving adult stem cells. But it said obtaining stem cells from a living embryo, even for the sake of effective therapies, was "gravely illicit."
It repeated its opposition to human cloning for both medical therapies and reproduction. Such techniques could result in an individual being subjected to a form of "biological slavery from which it would be difficult to free himself."
It noted therapeutic cloning techniques in which embryonic-type stem cells can be produced without destroying true embryos. The document didn't rule definitively on the technology, known as altered nuclear transfer, saying there were still questions about what was produced.
