A U.S. government study of an experimental HIV vaccine has been halted effective immediately, because the vaccine did not prevent HIV infection in some volunteers.
http://www.cbsnews.com/8301-204_162-57581454/government-halts-hiv-vaccine-trial-after-volunteers-infected/
http://www.cbsnews.com/8301-204_162-57581454/government-halts-hiv-vaccine-trial-after-volunteers-infected/
