Evaluation of a Boosting Regimen With Oral Cholera Vaccine

A Open Labeled Controlled Trial to Evaluate the Immune Response of a Boosting Regimen With Shanchol™, a Killed Whole Cell Oral Cholera Vaccine (WC-OCV), in Previously Immunized Adults and Children in Eastern Kolkata, India

Data demonstrates that Shanchol™ (killed bivalent oral cholera vaccine) provides protection over 3 years and data regarding the protective efficacy over five years is anticipated for 2012. Regardless at the end of five years, it may still be necessary to provide a booster dose or reimmunize with two doses to maintain protection in previously immunized populations. This study examines the immune protection and safety of providing a one and two dose boosting regimen of Shanchol™ given five years after the initial dose.

Inclusion Criteria:

All subjects must be presently enrolled in the Phase 3 NICED RCT of Shanchol™ and satisfy the following criteria at study entry:

1. Male or female adults aged 6 years and above, who are available for follow-up visits and specimen collection.

   • The subject should be able to continue in the study for the next 6 weeks
   • The subject (or parent/guardian) should be willing to provide 3 blood samples

2. Written informed consent obtained from the subjects or their parents/guardians, and written assent obtained from children aged 12 - 17 years.

3. Healthy subjects as determined by:

   • Medical history
   • Physical examination
   • Clinical judgment of the investigator

Exclusion Criteria:

1. individuals who are too weak to get out of bed to receive the vaccine
2. pregnant women (identified through verbal screening)
3. those less than 6 years of age
4. Receipt of cholera vaccine following 2009 (time of licensure and availability of Shanchol™ in India)