Leor Weinberger calls it hijacking the hijacker. In his lab at the Gladstone Institutes, he’s developed a technique for harnessing stray bits of HIV - a virus that infects and ultimately kills immune cells - and using them to attack the virus itself. His work, still preliminary and untested in animals or humans, is part of what some scientists are calling a “renaissance” in viral therapy. Giant advances in our understanding of how viruses work and how they can be manipulated have led to a growing field of research in using them to fight some of the world’s deadliest diseases.