Anthrax immunization: A series of six shots over six months and booster shots annually, the anthrax vaccine now in use in the USA was first developed in the 1950s and approved by the Food and Drug Administration for general use in 1970. It is produced by the Michigan Biologic Products Institute of Michigan's Department of Health and is given routinely to veterinarians and others working with livestock. In December, 1997 it was announced that all US military would receive the vaccine, as do the military in the UK and Russia, the reason being concern that anthrax might be used in biologic warfare.