After 25 years and billions of research dollars the world's scientists have been unable to develop a vaccine that provides immunity against AIDS.

Although there're been successes in developing medications to treat people infected with HIV/AIDS, there's been no progress in creating a vaccine, the Newark (N.J.) Star-Ledger reported Monday.

"It's seriously questionable whether there will ever be an effective vaccine for HIV," Ronald Desrosiers, an AIDS researcher affiliated with Harvard University, told the newspaper. "It would be the greatest good we could do for mankind, and we should try like hell (but) we are going to need to solve some fundamental science questions to lead us to a vaccine."

It was June 5, 1981, when five gay men were admitted to Los Angeles hospitals with a mysterious illness, the Star-Ledger said, noting it took another year before the disease was given a name: acquired immune deficiency syndrome, or AIDS.

HIV/AIDS has since infected approximately 65 million people and killed nearly 25 million.

Copyright 2006 by United Press International