[JURIST] US District Court Judge Emmet Sullivan Wednesday ruled [order text, PDF] that the Department of Defense (DOD) [official website] can give troops anthrax vaccinations on a voluntary basis. The ruling comes after Sullivan halted mandatory shots last October [JURIST report] in response to a lawsuit brought by six unnamed military personnel and civilian workers who objected to the mandatory vaccination. The October order [text, PDF] said the Food and Drug Administration [official website] had acted improperly in allowing experimental vaccinations in general use. Sullivan issued the new order after the DOD asked for a modification to the October order to allow for voluntary inoculations under a 2004 law which bolsters the government's ability to protect its troops against bioterrorism. Judge Sullivan wrote in the new order that Congress authorized the use of unapproved drugs based on a determination by the Defense Secretary of the existence of or potential for a military emergency against US forces facing the threat of attack with chemical, biological, radiological or nuclear weapons. The DOD had forced most US troops deployed in Iraq and Afghanistan to get the anthrax shot. Reuters has more.