Heavy hopes riding on an HIV vaccine were dashed as the vaccine proved so ineffective in a clinical trial that manufacturer Merck has ended the trial early. The vaccine had shown promise in animal and small-scale human tests but neither prevented nor reduced the severity of infection in a large-scale trial, the New York Times reports.
Scientists said the failure confirms the view that HIV is unlike other infections. Following the failure of an earlier conventional vaccine—one that stimulates the body to produce antibodies—this vaccine was designed to stimulate T-cells, a different component of the immune system. About 30 other AIDS vaccines are currently being tested.