The state Department of Health is not ready to commit to buying its full share of flu vaccine next winter, but it has asked the federal government to keep the state’s full share of extra vaccine available for an emergency. The state has to decide by the end of the year if it wants to buy all of it. The federal government plans to buy enough Taniflu and other medicines to reduce flu symptoms in more than 850,000 Missourians. Missouri has the option to buy another 600,000 doses for almost $9 million.