A team based at the Scripps Research Institute discovered a pair of antibodies that can block many strains of the HIV virus from multiplying and producing infections. The antibodies work on a part of the virus that researchers had previously ignored - one that is relatively stable and does not mutate as extensively as others, a characteristic that has frustrated previous attempts at producing a vaccine.
The findings were reported Friday in the journal Science.
Researchers isolated the two antibodies after taking blood samples from 1,800 HIV patients who had demonstrated resistance to serious infections. Those antibodies - called PG9 and PG16 - bind themselves to parts of two proteins on the virus's surface that help it invade cells.
The antibodies neutralized activity in around 75 percent of the HIV virus's 162 strains and could be used to treat those who have developed serious infections.
But the broader goal would be use them as the foundation of a vaccine.
There are currently at least 33 million people infected with HIV around the world, according to the World Health Organization.