Leading Article: Welcome to the life-saving pig

If it is ethical to eat a pig's liver, why was there ever any doubt that it is equally ethical to transplant it into a human? What's OK for the dinner table must be OK for the operating table, too. Not surprisingly, the Nuffield Council on Bioethics yesterday decided that there was no intrinsic ethical objection to xeno-transplantation - the use of animal organs to save human lives.

No doubt some will shudder. There will be some spasms of revulsion, a yuck factor at the idea of a pig kidney at work inside a human: the first transplants will spawn plenty of cartoons about pig-people, just as there once were about test-tube babies. But it will pass. There will also be objections from believers in a strong version of animal rights that it is wrong for animals to be bred solely for human purposes. But these pigs will be reared in relative luxury compared to farm animals. When it comes to saving lives, that objection, too, will pass.

The real issue, as the report points out, concerns safety. For the first recipients of the organs, this may not be the issue, for they are likely to be those who are close to death and for whom this is the last chance. It will take time to assess the benefits, but if results are good, there is a chance that these new techniques using genetically-engineered pigs will mean that humans can receive the organs without rejection.

There is no doubting the demand, for the number of human organs available for transplant has fallen sharply in recent years. Here we get into calculations which are harrowing, inescapable and ultimately life confirming. The compulsory wearing of helmets by motorcycle riders has reduced the number of young, fit people who die on ventilators. More sophisticated neurology means many who would have been put on ventilators now die far more quickly once it is established there is no hope for them. Even if we adopted the more sensible approach of assuming that all organs could be taken unless patients had previously registered objections, there would still never be enough organs to save all the lives of those who need them.

However there are two long-term issues that need to be addressed before we should proceed.

The first is a doomsday scenario, a remote but alarming risk that putting animal tissue into a human could create a new retrovirus as lethal as Aids. For this reason the report recommends that no transplants should begin until a government committee, chaired by Professor Ian Kennedy, has made a scientific assessment of the precise degree of risk.

The second issue is whether the NHS can afford the kinds of treatment these scientific advances make possible. If we cannot afford enough intensive care beds now, how will we cope when transplants using pig organs are available? The demand for transplants will grow dramatically if they are an outstanding success. The price of these transplants is unknowable, although they will be expensive to start with. But it is sure to create another pressing demand which the NHS will find it hard to ration.