Optimal Human Dose for GII.2 Norovirus (Snow Mountain) Challenge Studies

GII.2 Snow Mountain Norovirus Filtrate. Cohort 1: 1.2x10\^4 Genome Equivalent Copies (GEC) oral dose on Day 1. Cohort 2: either 1.2 x 10\^2 GEC or 1.2 x10\^6 GEC oral dose on Day 1, depending on the results of prior Cohort 1. Cohort 3: either 1GEC, 1.2 x 10\^1 GEC, 1.2 x 10\^2 GEC, 1.2 x 10\^3 GEC, 1.2 x 10\^5 GEC, or 1.2 x 10\^6 GEC, or 1.2 GEC x 10\^7 oral dose on Day 1, depending on the percentage of subjects with illness from Cohorts 1 and 2. Cohort 4: optimal dose of GEC as determined by the results of cohorts 1-3

Placebo: 80 ml of sterile water for oral administration