Hitting a moving target: AIDS vaccine could work against changeable site on HIV

A vaccine or other therapy directed at a single site on a surface protein of HIV could in principle neutralize nearly all strains of the virus--thanks to the diversity of targets the site presents to the human immune system. HIV infection is nearly always fatal, if untreated, because the virus is extremely effective at evading the human immune response. Its main strategy is to cover its most exposed parts, the flower-like envelope protein (Env) structures that grab and penetrate host cells, with...