Safety and immunogenicity of an improved oral inactivated multivalent enterotoxigenic Escherichia coli (ETEC) vaccine administered alone and together with dmLT adjuvant in a double-blind, randomized, placebo-controlled Phase I study

• DOI: 10.1016/j.vaccine.2014.10.069
• Publication Date: 2014-11-05T12:47:25Z
• Authors: Anna Lundgren; Louis Bourgeois; Nils Carlin; John Clements; Björn Gustafsson; Marianne Hartford; Jan Holmgren; Max Petzold; Richard Walker; Ann-Mari Svennerholm
• Keywords: Enterotoxigenic Escherichia coli; Toxoid

We have developed a new oral vaccine against enterotoxigenic Escherichia coli (ETEC), which is the most common cause of bacterial diarrhea in children developing countries and travelers.The was tested for safety immunogenicity alone together with double-mutant heat-labile toxin (dmLT) adjuvant double-blind, placebo-controlled Phase I study 129 Swedish adults. The consists four inactivated recombinant E. strains overexpressing major ETEC colonization factors (CFs) CFA/I, CS3, CS5, CS6 mixed an LT B-subunit related toxoid, LCTBA. Volunteers received two doses alone, plus 10 μg or 25 dmLT placebo. Secretory IgA antibody responses fecal samples secretions from circulating intestine-derived secreting cells were assessed as primary measures immunogenicity.The safe well tolerated; adverse events few generally mild no significant differences between subjects receiving placebo without adjuvant. As many 74% 83% showed mucosal to all five antigens about 90% vaccinees responded at least antigens. Subjects significantly increased anti-CS6 compared alone.The broadly immunogenic. further enhanced immune CF present low amounts vaccine. Based on these encouraging results, will be different age groups including infants Bangladesh protective efficacy travelers.