This was a cell-free vaccine in distinction to the live-cell Pasteur-style vaccine previously used for veterinary purposes. It is now manufactured by Porton Biopharma Ltd, a Company owned by the UK Department of Health. AVP is administered at primovaccination in three doses with a booster dose after six months. The active ingredient is a sterile filtrate of an alum-precipitated anthrax antigen from the Sterne strain in a solution for injection. The other ingredients are aluminium potassium sulphate, sodium chloride and purified water. The preservative is thiomersal (0.005%). The vaccine is given by intramuscular injection and the primary course of four single injections (3 injections 3 weeks apart, followed by a 6-month dose) is followed by a single booster dose given once a year. During the Gulf War (1990–1991), UK military personnel were given AVP concomitantly with the pertussis vaccine as an adjuvant to improve overall immune response and efficacy. American anthrax vaccines
The United States undertook basic research directed at producing a new anthrax vaccine during the 1950s and 60s. The product known as Anthrax Vaccine Adsorbed (AVA)—trade name BioThrax—was licensed in 1970 by the U.S. National Institutes of Health (NIH) and in 1972 the Food and Drug Administration (FDA) took over responsibility for vaccine licensure and oversight. AVA is produced from culture filtrates of an avirulent, nonencapsulated mutant of the B. anthracis Vollum strain known as V770-NP1-R. No living organisms are present in the vaccine which results in protective immunity after 3 to 6 doses.
Investigational anthrax vaccines
A number of experimental anthrax vaccines are undergoing pre-clinical testing, notably the Bacillus anthracis protective antigen—known as PA (see Anthrax toxin—combined with various adjuvants such as aluminum hydroxide (Alhydrogel), saponin QS-21, and monophosphoryl lipid A (MPL) in squalene/lecithin/Tween 80 emulsion (SLT). One dose of each formulation has provided significant protection (> 90%) against inhalational anthrax in rhesus macaques. Omer-2 trial: Beginning in 1998 and running for eight years, a secret Israeli project known as Omer-2 tested an Israeli investigational anthrax vaccine on 716 volunteers of the Israel Defense Forces. The vaccine—given under a seven-dose schedule—was developed by the Nes Tziona Biological Institute. A group of study volunteers complained of multi-symptom illnesses allegedly associated with the vaccine and petitioned for disability benefits to the Defense Ministry, but were denied. In February 2009, a petition from the volunteers to disclose a report about Omer-2 was filed with the Israels High Court against the Defense Ministry, the Israel Institute for Biological Research at Nes Tziona, the director, Avigdor Shafferman, and the IDF Medical Corps. Release of the information was requested to support further action to provide disability compensation for the volunteers. In 2014 it was announced that the Israeli government would pay $6 million compensation to the 716 soldiers who participated in the Omer-2 trial. In 2012, B. anthracis isolate H9401 was obtained from a Korean patient with gastrointestinal anthrax. The goal of the Republic of Korea is to use this strain as a challenge strain to develop a recombinant vaccine against anthrax.