WITHIN days of infection, the AIDS virus destroys more than half of the immune cells that might recognise and help fight it, US researchers have found. The discovery might force a re-evaluation of how to tackle the deadly infection. Two separate studies in monkeys showed that SIV, the monkey version of the human immunodeficiency virus or HIV, attacked CD4 memory T-cells right away and wiped out more than half of them. "The findings may require a rethink of strategies to design HIV drugs and vaccines," said Dr Mario Roederer, of the National Institute of Allergy and Infectious Diseases. The findings...