The National Institutes of Health has decided to cancel a large-scale test of an experimental AIDS vaccine, saying that more focused research is needed on the way such vaccines interact with the immune system. The trial, known as PAVE 100, was designed to include more than 8,500 people.
The vaccine to be tested, developed by the NIH, was similar in some regards to a vaccine developed by pharmaceutical company Merck that failed in a study last fall. Both vaccines, rather than preventing infection, were designed to stimulate an immune response that would help infected individuals to keep HIV levels in check within the bloodstream.
Dr. Anthony Fauci, head of the National Institute on Allergy and Infectious Diseases, discusses the challenges researchers face when developing AIDS vaccines.