PERU-15, AN IMPROVED LIVE ATTENUATED ORAL VACCINE CANDIDATE FOR VIBRIO-CHOLERAE-01

Cholera vaccine candidate Peru-15 was derived from a Vibrio cholerae O 1 El Tor Inaba strain by deleting the cholera toxin genetic element, i ntroducing the gene encoding cholera toxin B subunit into recA, and sc reening for nonmotility. In a controlled study, Peru-15 (2 x 10(8) cfu ) was administered to 11 volunteers. No vaccinee developed diarrhea, a nd 10 of 11 had >4-fold rises in vibriocidal antibody titers. One mont h later, 5 vaccinees and 5 control volunteers were challenged with wil d type V. cholerae O1. Four of 5 controls developed diarrhea (mean, 1. 9 L). Two Peru-15 vaccinees developed diarrhea, 1 with <0.3 L and 1 wi th similar to 1.0 L; this latter volunteer had not developed a signifi cant vibriocidal immune response to vaccination. Peru-15 shows promise as a single-dose, oral cholera vaccine that is safe, immunogenic, and protective.