The MACS investigators, and other researchers, defend the slow pace of research as a function of numbers. The first generation of AIDS patients, in the mid-1980s, had no effective treatments for a decade, and died in overwhelming numbers, leaving few survivors to study.

Those survivors, like Mr. Holloway, gaunt from chemotherapy and radiation and mostly housebound, lurch from crisis to crisis. Mr. Holloway says his adjustment strategy is simple: “Deal with it.” Still he notes, ruefully, that his father has no medical complaints other than arthritis, failing eyesight and slight hearing loss.

“I look at how gracefully he’s aged, and I wish I understood what was happening to my body,” Mr. Holloway said during a recent home visit from his case manager at the Howard Brown Health Center here, a gay, lesbian and transgender organization. The case manager, Lisa Katona, could soothe but not inform him. “Nobody’s sure what causes what,” Ms. Katona told Mr. Holloway. “You folks are the first to go through this and we’re learning as we go.”

Mr. Holloway is uncomplaining even in the face of pneumonia and a 40-pound weight loss, both associated with his cancer treatment. Has the cost been too high? He says it has not, “considering the alternatives.”

Halfway across the country, Jeff, 56-year-old New Yorker who was found to have AIDS in 1987, said he asks himself that question often.

Jeff, who asked that he not be fully identified, has had one hip replacement because of a condition called avascular necrosis, the death of cells from inadequate blood supply, and needs another to avoid a wheelchair. Many experts think that avascular necrosis is caused by the steroids many early AIDS sufferers took for pneumonia.

Image John Holloway, 59, survived AIDS but has more health problems than his 84-year-old father. Credit... Nicole Bengiveno/The New York Times

“The virus is under control, and I should be in a state of ecstasy,” he said, “but I can’t even tie my own shoe laces and get up and down the subway stairs. ”