Evaluation of BioThrax® and AV7909 anthrax vaccines in adults 66 years of age or older.

Background: Multiple Anthrax vaccines are licensed or in development for post-exposure prophylaxis in individuals 18 to 65 years of age. No information exists on anthrax vaccines in populations over the age of 65. It is critical that we assess the capacity of anthrax vaccines to generate a protective immune response in older individuals.