By Kyung M. Song Seattle Times health reporter
Scientists have known since 1984 that HIV causes AIDS. But for more than two decades since, the cunning human immunodeficiency virus has foiled all efforts to develop a vaccine.
As nearly a thousand of the world's top vaccine researchers gather in downtown Seattle this week for the four-day AIDS Vaccine 2007 Conference, some of them say the most realistic goal now isn't a vaccine to prevent HIV infection, but rather one that prevents HIV from being passed on.
"The HIV virus is an elusive virus," said Dr. Glenda Gray, a pediatrician and co-founder of the perinatal HIV research unit at the Chris Hani Baragwanath Hospital in Soweto, South Africa.
"I don't think anyone would have expected that it would take so long to find a vaccine."
At the same time, vaccine hunters remain unshaken in their belief that a vaccine is the only way to eventually eradicate AIDS. That's because it is clear now that it's impossible to completely eliminate the biggest sources of infection: unprotected sex, sharing needles, and childbearing and breastfeeding by infected women.