Randomization and blinding
Each study was conducted in several cohorts, and animals were randomized to different treatment groups, challenge days (cohorts) and order of challenge (same as cage order) in each cohort. Randomizations were performed with StataBoth studies were conducted in a blinded fashion such that the personnel involved in the study (study director, technicians performing the dosing, technicians observing the animals, and microbiologists) did not know the treatment group identity of animals during the in-life phase of the study. The study pathologist was blinded until all histopathology slides were read.