Homo sapiens Phenotype or Genotype. Homo sapiens

Evaluation of vaccines against typhoid and other enteric pathogens may be informed by better understanding the relationship between the effector immune response and the gut microbiota. Longitudinal fecal samples were collected from healthy adults recruited in Oxford, UK. Volunteers received 3 doses of oral Ty21a (a licensed live attenuated typhoid vaccine, strain Ty21a), a single dose of M01ZH09 (an attenuated live typhoid vaccine candidate strain) or placebo, followed 28 days later by challenge with 104CFU wild-type (wt) S. Typhi (Quailes strain) and monitoring of clinical symptoms and hematological and biochemical responses, and daily microbiological sampling. Stool samples were collected at the screening interview (Baseline 1), prior to the first vaccination visit (Baseline 2), two time-points during vaccination (Day -28 and -26) for placebo and M01ZH09 groups while four time-points during vaccination (Day -32, -30, -28, -26) for Ty21a group, prior to challenge with S. Typhi (Day 0), and five time-points after challenge at day 0 12h, day 1, day 3, day 7 and day 10. Our approach incorporated longitudinal 16S rRNA and metatranscriptomic analyses of stool samples.