Dr. Dan Barouch of the Beth Israel Deaconess Medical Center, who led the study, noted the failure last year of the V520 vaccine developed by Merck & Co. led many to question the value of pursuing development of T-cell-based HIV-1 vaccines.

But the new study showed an improved vaccine produced strong T-cell immune responses, and long-term immune control of a simian immunodeficiency virus (SIV) in monkeys.

"Despite the disappointing setbacks in HIV-1 vaccine development this past year … our data show that T-cell vaccines that elicit greater magnitude, breadth and quality of immune responses as compared with the Merck vaccine can result in improved protection in the rhesus monkey model of AIDS," said Barouch.

The study that included scientists from the University of California-Irvine, Duke University, the New England Primate Research Center and the Netherlands corporations TNO Biosciences and Crucell Holland BV appears in the advance of print online edition of the journal Nature.