SAN DIEGO: A successful AIDS vaccine remains elusive, but researchers say aggressive, early anti-viral therapy might provide a way to derail the spread of disease.

The goal is to catch new AIDS cases early and administer therapy to reduce the amount of virus in the patient's system.

Anti-retroviral therapy has increased in the past five years. But it's been given too late in the course of infection.

By the time people start therapy they have infected most of those that they would have infected anyway. That's according to Brian Williams of the South African Center for Epidemiological Modeling and Analysis.

The research was presented Saturday at the annual meeting of the American Association for the Advancement of Science in San Diego.