EVALUATION OF PERU-15, A NEW LIVE ORAL VACCINE FOR CHOLERA, IN VOLUNTEERS

A new live oral cholera vaccine, Peru-15, was studied for safety, immu nogenicity, and excretion in 2 groups of healthy volunteers. Twelve in patient volunteers received freshly harvested vaccine in doses of eith er 10(7) or 10(9) cfu. Subsequently 50 outpatient volunteers received freeze-dried vaccine in doses of 10(8) or 10(9) cfu or placebo in a th ree-cell, double-masked, placebo-controlled trial. The strain was well tolerated at all dose levels, and it stimulated high levels of vibrio cidal antibodies in most inpatient volunteers and in all outpatient vo lunteers. Although antitoxin responses were less frequent and of lower magnitude than the vibriocidal responses, antitoxin responses were se en in >60% of the outpatient volunteers. About 60% of the volunteers e xcreted the vaccine in their feces; however, fecal excretion did not c orrelate with serologic responses. It is concluded that Peru-15 is a s afe and immunogenic oral vaccine for cholera.