Effect of Extended Dose Intervals on the Immune Response to Oral Cholera Vaccine

Shanchol is a bivalent (O1 and O139 serotypes) vaccine using a heat-killed classical Inaba strain and a formalin-killed classical Ogawa strain produced by Sanofi. Shanchol requires no oral buffer for administration, is approved for persons greater than 1 year of age, and requires 2 doses at two-week intervals. It became World Health Organization (WHO) prequalified in 2011.

The Adjusted Dose Oral Cholera Vaccine is given in two doses, with the second dose given at six months, rather than the manufacturer described 2 week interval between first and second dose.