Mucosal immune responses against an oral ETEC vaccine evaluated in clinical trials.

Enterotoxigenic Escherichia coli, ETEC, is a leading cause of mortality and morbidity in children in low-income countries. We have tested an oral ETEC vaccine, ETVAX, consisting of inactivated E. coli over-expressing the most prevalent colonization factors and a toxoid, LCTBA, administered together with a mucosal adjuvant, dmLT, for capacity to induce mucosal immune responses and immunological memory against the primary vaccine antigens, i.e. colonization factors, LTB and O antigen. The studies show that ETVAX could induce strong intestine-derived and/or fecal immune responses in a majority of vaccinated Swedish adults and in different age groups, including infants, in Bangladesh.