(Manuel Valdes | The Associated Press) Timothy Ray Brown poses for a photograph, Monday, March 4, 2019, in Seattle. Brown, also known as the "Berlin patient," was the first person to be cured of HIV infection, more than a decade ago. Now researchers are reporting a second patient has lived 18 months after stopping HIV treatment without sign of the virus following a stem-cell transplant. But such transplants are dangerous, cannot be used widely and have failed in other patients.