FUT1 and infection: Only the vaccine using bacteria grown with galactose was protective from infection, and it induced a higher rate of O-antigen seroconversion (a = fourfold rise in antibody from baseline) than the vaccine containing bacteria grown without galactose (17% vs 4%, p <0.04), but this did not correlate with protection from infection Rates of seroconversion to H-antigen were higher in both groups (60% in galactose negative and 60%in galactose positive) but there was minimal seroconversion to Vi-antigen (2% in galactose negative and 0% in galactose positive).