In recognition of stunning advances in both clinical and basic research related to AIDS, the editors of Science have chosen new weapons against HIV  as the Breakthrough of the Year for 1996. The award, an annual event, salutes new drugs and a new understanding of how the virus infects cells--advances that are bringing hope to those infected with HIV after years of stalemate in the war on AIDS.
An article describing the background to the award notes that these developments began last December, when the first of a new class of drug, the protease inhibitors, came on the market. Protease inhibitors jam the active site of a key HIV enzyme, and, when taken in combination with AZT or other drugs, can reduce the virus to undetectable levels in the blood. These potent drug cocktails are no magic bullet, and only a fraction of HIV-infected people can afford to take them, but they block the virus to a degree undreamed of only a few years ago.
In the basic research realm, Science notes that researchers this year identified long-sought anti-HIV factors. They turned out to be chemokines, small polypeptide molecules that are part of the immune system's armory of natural weapons. In a series of reports throughout the year, researchers found that in order to get into a cell, HIV must first bind to a cell surface receptor that normally receives the chemokines, and the virus cannot infect people born with defective chemokine receptors. This insight opens the door to new therapeutics and perhaps even vaccines.
Science also honored nine research milestones with potential benefits to society as runners-up for Breakthrough of the Year. They include research on the origins of life , which fired the public imagination with evidence of possible ancient life on Mars; new kinds of lasers  that may one day make better CD-ROMs; and the decoding of cellular self-destruct programs , which may have implications for research in diseases such as cancer and stroke.