Federal investigators on Thursday were in plans for major testing of an experimental vaccine which was developed by the National Institutes of Health - the most recent rain failure last September of the same candidate from drugmaker Merck & Co., which left some volunteers more vulnerable to HIV infection. That caused the cancellation due to concerns of its safety.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said the decision to cancel the study was internally.

According to Merck vaccine failure, Fauci first delayed and then reduce the proposed $ 160 million testing a vaccine against NIH. The study was conducted under the name "100 PAVES.

Concern about the similarities between his test vaccine and Merck's vaccine showed increased susceptibility to those that received it.

The vaccine had many hopeful for a cure for AIDS but it looks like it has to be paused for safety issues.