The anthrax vaccine is a cell-free filtrate vaccine, which means it uses dead bacteria as opposed to live bacteria. BioPort Corporation is the sole manufacturer of the anthrax vaccine. BioPort, whose headquarters is located in Lansing, Michigan, is owned by multiple shareholders. Annual booster injections of the vaccine are required to maintain immunity. Like all vaccines, anthrax vaccine may cause soreness, redness, itching, swelling, and lumps at the injection site.
Lumps can persist a few weeks, but eventually disappear.
Injection-site problems occur about twice as often among women. Larger reactions at the injection site occur in about one in a hundred vaccine recipients. Again, these symptoms usually go away after a few days. Serious events, such as those requiring hospitalization, are rare. They happen about once per 50,000 doses.