Evaluation of a Boosting Regimen With Oral Cholera Vaccine

"This killed, whole cell, bivalent vaccine will be presented as a creamish white suspension. Upon storage, a white sediment and clear supernatant may be observed. The recommended dose (1.5ml) of the vaccine must be administered orally. The primary vaccination schedule consists of two doses given at an interval of two weeks. After vigorous shaking of the vial, 1.5 ml should be poured into the mouth of the recipient, followed by water ad libitum. The vaccine can alternatively be administered with a disposable syringe (without needle) after removing the contents from the vial and squirted into the mouth of the recipient.~Vaccine is administered in 1.5 mL vials by mouth in 2 doses, given 2 weeks apart. The vaccine appears as a creamy white suspension."

"This killed, whole cell, bivalent vaccine will be presented as a creamish white suspension. Upon storage, a white sediment and clear supernatant may be observed. The recommended dose (1.5ml) of the vaccine must be administered orally. The primary vaccination schedule consists of two doses given at an interval of two weeks. After vigorous shaking of the vial, 1.5 ml should be poured into the mouth of the recipient, followed by water ad libitum. The vaccine can alternatively be administered with a disposable syringe (without needle) after removing the contents from the vial and squirted into the mouth of the recipient.~Vaccine is administered in 1.5 mL vials by mouth in 2 doses, given 2 weeks apart. The vaccine appears as a creamy white suspension."

No intervention will be given to this arm of past placebo recipients. To ensure that boosting was not due to natural exposure to Vibrio cholera, we will compare subjects in the boosting arm to this no intervention arm.