PharmAthene preclinical data

In rabbits, doses of intramuscular SparVax containing 0.1, 0.3 and 1 µg of recombinant protective antigen (rPA) given on days 0 and 28 each significantly increased survival rates following challenge with Bacillus anthracis spores on day 70 vs. control animals that received either no immunization or received saline (87.5%, 62.5% and 87.5%, respectively, vs. 0%, p<0.01 for all). All animals that received SparVax generated an antibody response that was higher than controls. However, only animals receiving the 3 highest doses - 0.1, 0.3 and 1 µg - of the vaccine maintained significantly higher levels of neutralizing antibodies until the time of challenge. Data were presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy in Denver. ...