Anthrax AV7909 Liquid vs Lyophilized

This is a randomized, parallel-group, double-blind, Phase 1 study designed to assess safety, tolerability and immunogenicity of 2 formulations of adjuvanted anthrax vaccine (AV7909), lyophilized and liquid. Forty healthy young adults, 18 to 45 years old, inclusive, who meet all eligibility criteria, will be randomly allocated to one of two study groups in a 1:1 ratio: 20 will receive AV7909 as the thermostable lyophilized product and 20 will receive AV7909 as the liquid product. Stratification by age category and by gender will assure that near equal numbers of younger (18-30 years) and older (31-45 years) males and females are assigned to each vaccine. The vaccines will be given intramuscularly in a 2-dose schedule, 2 weeks apart. Safety will be assessed by evaluation of non-serious unsolicited Adverse Events, Serious Adverse Events (SAEs), Medically Attended Adverse Events (MAAEs), Adverse Events of Special Interest (AESIs) \[the AESIs collected in this study are Potentially Immune-Mediated Medical Conditions (PIMMCs)\], and by laboratory evaluations. Reactogenicity will be measured by the occurrence of solicited injection site and systemic reactions in the week after each study vaccination. Immunogenicity testing will include performing serological assays to assess for toxin neutralizing antibodies (reported as ED50 and NF50), the gold standard assay for assessing response and protection following anthrax vaccines, prior to vaccination and on approximately Days 8, 15, 22, 29, 64, 195, and 380. In addition, anti-PA IgG antibodies will be measured by ELISA from the serum of participants, on those same days. The primary safety objective of this study is to assess the safety of lyophilized and liquid formulations of AV7909. The primary tolerability objective is to assess the tolerability of lyophilized and liquid formulations of AV7909. The secondary immunogenicity objective of this study is to obtain initial estimate of comparative immunogenicity of liquid and lyophilized formulations of AV7909.