NEXT MONDAY the United Nations Security Council will, for the first time in its history, convene to discuss action on a health issue. Also for the first time, the meeting will be chaired by an American vice president. The health issue in question is the spread of the HIV virus: Since AIDS, the disease to which the virus leads, is killing far more people than war, it richly deserves the Security Council's attention. The question is what to do about it.

The first answer is to resist the temptation to place excessive hope in the wonder drugs that have cut mortality from AIDS in rich countries. These drugs cost around $20,000 per person per year; many of the poor countries that bear the brunt of AIDS have annual health budgets of less than $20 per person. There have been welcome efforts to reduce the cost of treatment: Last year the pharmaceutical industry allowed firms in South Africa to distribute cheaper copies of their products.

But even if the cost of treatment could be radically reduced, it would remain impractical in much of the developing world. Anti-HIV drugs need to be administered with a precision that rudimentary health infrastructures cannot aspire to.

The second answer is to invest in the development of a cheap, easily delivered vaccine--but not to expect a quick victory. Even if a vaccine were discovered tomorrow, its efficacy could not be known until it is tested; and tests involve monitoring large groups of people over extended periods. There are plans afoot for the world's eight leading countries to promise $500 million each toward the future cost of delivering a vaccine to the poor world: This would give the drug companies a powerful incentive to come up with one. But that excellent scheme cannot save the millions likely to become infected over the next half-decade. In sub-Saharan Africa, 10 people are infected every minute.

Since science is unlikely to provide a silver bullet in the medium term, there is no option but to change human behavior. That sounds like a hopeless task: There have been calls for safe sex in the developing world for more than a decade, and yet the epidemic has progressed monstrously. But changing behavior is not in fact impossible. The countries that have tried it seriously have managed. Thailand, for example, has succeeded in getting prostitutes to insist on condoms. Senegal has kept the incidence of HIV infection below 2 percent. Uganda's education campaign, focusing both on values and on practical information, has persuaded its youth to delay the first sexual experience by an average of two years; the infection rate among pregnant women in towns fell from 37 percent to around 15 percent during the 1990s.

Other developing countries need to follow this example. To do this, they need to go beyond spreading the simple facts of the disease: Study after study in Africa has found that people know about AIDS but still do not change their behavior. In order to make progress, governments need to fight the presumption that multiple sexual conquests are a mark of manly virtue: They could begin by prosecuting rapists seriously, including the many teachers who routinely have sex with their pupils. At the same time, governments need to treat decently those who are infected, so that the stigma of AIDS weakens. So long as that stigma persists, people will not admit to having the disease, and so will continue to spread it.

This set of policies will be expensive. The humane treatment of sufferers is a monumental task in regions such as southern Africa, where one in four adults are thought to carry HIV. In his speech before the Security Council next week, Vice President Al Gore will do the world a service by focusing attention on this era's plague. But he should also spur the developed world to give more aid to developing countries with serious AIDS policies. At present, the United States spends nearly $900 million a year on fighting the disease within the United States, and the problem here is far from solved. All the sub-Saharan countries combined have a mere $160 million to spend on their efforts--and the challenge they face is much, much bigger.