A Sound Rationale Needed for Phase III HIV-1 Vaccine Trials

Concerns are expressed by a group of AIDS researchers about the U.S. government9s plans to conduct a phase III trial of a combination HIV-1 vaccine in Thailand despite the cancellation of a trial of a very similar combination vaccine in the U.S.A. last year. One of the vaccine components, recombinant monomeric gp120, has already been shown to be ineffective in phase III trials in Thailand and the United States; the other component, a recombinant canarypox vector, is also poorly immunogenic. The scientific rationale that has been offered for the new trial in Thailand is considered by the authors to be weak.