SAN FRANCISCO (MarketWatch) -- Scientists at the National Institute of Allergy and Infectious Diseases have found two antibodies that can stop more than 90% of the known virus strains that cause AIDS, the National Institutes of Health said Thursday. "The discovery of these exceptionally broadly neutralizing antibodies to HIV and the structural analysis that explains how they work are exciting advances that will accelerate our efforts to find a preventive HIV vaccine for global use," said NIAID director Anthony Fauci in a statement. The naturally occurring antibodies, called VRC01 and VRC02, neutralize more HIV strains than any other known antibodies, the NIH said.