Nor did it find any convincing evidence that people face elevated risk of developing adverse health effects over the longer term, although data are limited in this regard (as they are for all vaccines)." Side effects of AVA were found to be "comparable to those observed with other vaccines regularly administered to adults". The committee concluded that AVA is "safe and efficacious" for pre-exposure prevention of inhalational anthrax. It also asserted that a new and improved anthrax vaccine might have greater assurance of consistency than AVA and recommended licensure of a new vaccine requiring fewer doses and producing fewer local reactions.In the months after the October 2001 anthrax letters attacks, Washington and New York area mail sorters were advised to receive prophylactic vaccination with AVA. Owing to the controversy surrounding the administration of the vaccine to military personnel, however, some 6,000 US Postal Service employees balked at this, preferring to take their chances with the risks of residual anthrax spores in the workplace.BioPort changed its name to Emergent BioSolutions in 2004. Injunctions and FDA re-reviews (2004-2006)
Despite the positive IOM assessment, mandatory vaccinations of military personnel were halted due to an injunction which was put into place on October 27, 2004. The injunction cast questions about numerous substantive challenges regarding the anthrax vaccine in footnote #10, yet the procedural findings centered on FDA procedural issues, stating that additional public comment should have been sought before the FDA issued its Final Rule declaring the vaccine safe and effective on 30 December 2003.
The shelf-life of AVA is reported to be three years when stored between 2 °C and 8 °C (36 °F and 46 °F) and never frozen. History
Initial research and development (1954-1970)
The vaccine efficacy of AVA in humans was initially established by Philip S. Brachman of the United States Public Health Service (USPHS) in a controlled study undertaken between 1954 and 1959. The study field sites were four wool-sorting mills in the northeastern United States where employees were sometimes exposed to anthrax spores in the course of their work. Over the five years, 379 vaccinees were compared against 414 unvaccinated control subjects. There were 23 cases among controls (5 of them inhalation anthrax) compared with 3 cases among vaccinated (0 inhalation cases). The vaccine was judged to have a 92.5% vaccine efficacy against all types of anthrax experienced. Subsequently, there were no controlled clinical trials in humans of the efficacy of AVA due to the rarity of the condition (especially in the inhalational form) in humans and the ethical inadmissibility of conducting dangerous challenge studies in human subjects. Supportive animal challenge studies were done, however, showing that unvaccinated animals uniformly die whereas vaccinated animals are protected. About 95% of rhesus monkeys (62 of 65) survived challenge, as did 97% of rabbits (114 of 117). Guinea pigs (which are a poorer model for human anthrax than are monkeys or rabbits) showed a 22% protection (19 of 88).