CHICAGO: A powerful infusion of HIV-fighting antibodies beat back a potent form of the virus in monkeys and kept it at bay for weeks, US government scientists and a team led by Harvard University found, offering a potential next step in the battle against human HIV.

The two studies, published on Wednesday in the journal Nature, involve the use of rare antibodies made by 10 percent to 20 percent of people with HIV that can neutralize a wide array of strains.