THOSE concerned about the social implications of the new biology should consider the human immune system. Molecular biologists are learning to use it in novel ways.
Their intentions are benign and their objectives beneficial. But their work may sometimes have serious ethical implications. The effort to develop an oral birth-control vaccine is a current case in point.
If effective, this would induce a human body (male or female) to develop an immunity to human eggs and sperm. It would avoid the disturbance of body chemistry and side effects of birth-control medications now used. It would be inexpensive to produce. It wouldn't need refrigeration and could be easily reconstituted in the field. Thus it could be used freely anywhere in the world.
It could also be used surreptitiously. Someone could slip it into food. It could even make an ugly reality of the old joke about ``something in the water.''
Biologist Roy Curtiss III, who leads this research at Washington University in St. Louis, agrees that the technology might ``be used in ways that would pain me.'' Discussing this with science writers during the Council for Advancement of Science Writing's annual ``New Horizons in Science'' briefings in St. Louis last month, he raised the issue of ``informed consent.'' He said he hopes the vaccine's use would be democratically controlled.
We don't face that problem yet. There's a lot of research to be done before Dr. Curtiss and his colleagues will have a practical birth-control vaccine. That gives those concerned with biomedical ethics time to think through the ethical implications.
The research itself is a tribute to the skill of the molecular engineer. Curtiss and his colleagues are trying to use a bad ``bug'' for a good purpose. It's a strain of the salmonella bacterium associated with food poisoning. Genetic engineers have learned how to remove what they believe to be the genetic instructions that make it dangerous. They also can give salmonella new instructions that enable it to produce molecules - usually proteins - normally associated with other organisms including human eggs and sperm.
The birth-control scheme would make use of the body's immune system. It works like this: When an animal's immune system detects foreign molecules, it makes what biologists call antibodies to combat the invaders. These antibodies are proteins that attach themselves to the foreign molecules neutralizing them. The system then destroys the invading organisms that produce them. This is called an immune response. Once produced, it tends to persist, giving an animal or human continuing immunity against the foreign organisms.
Curtiss's team is using nonvirulent salmonella strains to induce what amounts to immunity against pregnancy. They have engineered the bacteria to produce proteins associated with eggs and sperm. The bacteria then stimulate an animal's immune system to do what it doesn't do naturally - act against a species' own eggs and sperm.
Research so far indicates that the scheme works in pigs and chickens. Curtiss says his goal is to develop a birth-control method that is harmless, reversible, and cheap. He does not yet know, for sure, that he can do it. But it is not too soon to begin to think about controlling its use. It could be an effective tool to help limit overpopulation. Its misuse could be a nightmare.