After a decade of disappointments, AIDS researchers may finally have blown the virus’s cover. A flurry of recent studies using new and more powerful antiviral drugs have captured a radically new picture of how the virus overwhelms the immune system. While it may take years for a person infected with the virus to get sick and die, that does not mean the virus is slow moving; all the while, it now seems, a silent but feverish battle is under way in the patient’s blood, with more than a billion immune cells being sacrificed each day to hold the line against a rapidly proliferating virus--which ultimately triumphs by the sheer force of its even greater numbers. This frightening-sounding picture, AIDS researchers are saying, just might--might--be good news. If the infection is caught early enough, before the tide has turned irrevocably against the immune-system defenders, combinations of antiviral drugs might hold the virus in check. We might then be able to live with it.
Until now, one of the central puzzles of AIDS has been the presence in the blood of such low levels of HIV, the human immunodeficiency virus. Shortly after a person becomes infected, the virus count in the blood rises, prompting an aggressive immune response. The blood level of the virus then drops, and it apparently retreats to the lymph nodes and other hiding places. It may take years for the virus count to rise again-- but eventually it almost always does. At that point the virus begins to wipe out T4 cells, and the disease enters its debilitating stage. T4 cells are the beat cops of the immune system, the ones that call in reinforcements whenever they encounter a cell infected by any kind of virus; as their numbers slowly dwindle, the patient falls prey to the opportunistic infections that ultimately, almost invariably, kill him.
