Human trial for vaccine against HIV is canceled
By Lawrence K. Altman Plans for a large human trial of a promising government-developed HIV vaccine in the United States were canceled Thursday because a top federal official said scientists realized that they did not know enough about how HIV vaccines and the immune system interact. The decision is a major setback in an effort to develop an HIV vaccine that began 24 years ago when government health officials promised a marketed vaccine by 1987. Health officials have long contended that such a vaccine would be their best weapon to control the AIDS pandemic.