Somewhat like a vaccine for HIV, a cure has been on the horizon yet out of reach for a frustratingly long time. "I think it's fair to say that the score card is not very impressive," Mario Stevenson, chief of the division of infectious disease at the University of Miami Medical School, told the audience at a the plenary session of the Conference on Retroviruses and Opportunistic Infections (CROI), which is going on in Boston this week.