Within days of infection, the AIDS virus destroys more than half of the immune cells that might recognize and help fight it -- a finding that may force a re-evaluation of how to tackle the deadly infection, two teams of U.S. researchers reported on Sunday. Two separate studies in monkeys showed that SIV, the monkey version of the human immunodeficiency virus or HIV, attacks CD4 memory T-cells right away and wipes out more than half of them. "The findings may require a rethink of strategies to design HIV drugs and vaccines," Dr. Mario Roederer of the National Institute of Allergy and Infectious Diseases and colleagues said in one of two reports published in the journal Nature. The findings will be difficult to replicate in people, because most people do not know the moment they are infected with the AIDS virus, which gradually destroys the immune system, leaving patients vulnerable to numerous infections. But SIV is a good model and works in a similar way. Both teams worked with monkeys that they infected with SIV. They watched what happened to their immune cells. Right away the virus attacked the CD4 T-cells that had the correct configuration for the virus. Normally during an infection such cells would recognize and latch onto an invader, helping other components of the immune system destroy it. --More 2347 Local Time 2047 GMT
