An Open Label Non-inferiority Trial Assessing Vibriocidal Response of a Killed Bivalent Oral Cholera Vaccine Regimen following a Five Year Interval in Kolkata, India.

Background The bivalent killed oral cholera vaccine (OCV) provides 65% cumulative protection over five years. It remains unknown whether a boosting regimen can maintain protection in previously immunized populations. This study examines the immunogenicity and safety of an OCV regimen given five years following initial dosing.