2.7. Statistical Analysis

Pairwise log rank tests were performed to compare all pairs of groups when time to death was considered in addition to overall survival. Furthermore, Kaplan-Meier curves associated with time to death were plotted for each group. Noninferiority tests were performed to compare the survival proportions between each pair of groups immunized with a specific dilution.

Logistic regression analysis was performed to identify the relationship between immune response and survival for the AV7909 vaccinated animals. Individual TNA NF₅₀ values less than the LOQ replaced with the respective LOQ. A similar logistic regression analysis was performed including all AV7909-vaccinated groups that included effects for vaccine type (thermostable or liquid) and the interaction between vaccine type and immune response. Quantitative bacteremia with values recorded as positive (“+”) and those less than the LOQ replaced with LOQ. Quantitative bacteremia values reported as zero were replaced with the limit of detection (LOD).