This is a randomized, double blind, placebo controlled trial to confirm the safety and determine the immune response of the killed oral cholera vaccine in healthy adults and children in Ethiopia.

This study serves as a bridging trial to evaluate the safety and immunogenicity of a two dose regimen of the WC-OCV (Shanchol®) in Ethiopian population. In order to assess whether the bivalent killed oral cholera vaccine may be used safely among those who are most at risk for cholera, we need to determine the safety and immunogenicity of the killed oral cholera vaccine. The vaccine was evaluated in a large number of human subjects in India Vietnam, and Bangladesh, in which it has demonstrated safety, immunogenicity, and clinical protective efficacy. Though we do not expect the vaccine to act differently in the Ethiopian population, we aim to confirm our presumptive understanding that two doses of WC-OCV is safe and immunogenic in healthy volunteers at one year and above (exclusive of pregnant women). Findings from this study can pave the way for the possible use of the killed whole cell oral cholera vaccine in both endemic and outbreak settings at a larger scale.

Inclusion Criteria:

1. Male or female adults aged 18 years and above; and children aged 1 -17 years who is available for follow-up visits and specimen collection.

   • The subject should be able to continue in the study for the next 4 weeks
   • The subject (or parent/guardian) should be willing to provide 3 blood samples

2. For females of reproductive age, non-pregnant (as determined by urine pregnancy test).

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

4. Healthy subjects as determined by:

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

Exclusion Criteria:

1. Ongoing chronic recurring illness which may cause systemic symptoms as judged by the investigating physician.
2. Ongoing acute illness.
3. For females of reproductive age: Pregnancy (or females planning to become pregnant during the study period; as determined by verbal screening)
4. Immunocompromising condition or on chronic systemic steroid therapy
5. Diarrhea (3 or more loose/more watery stools within a 24-hour period) within 6 weeks prior to enrollment
6. Intake of any anti-diarrhea medicine in the past week
7. Abdominal pain or cramps, loss of appetite, nausea, or vomiting in the past 24 hours
8. Temperature ≥38ºC (oral or axillary) warrants deferral of the vaccination pending recovery of the subject
9. Previous hypersensitivity to formaldehyde.
10. Receipt of immunoglobulin or any blood product during the past 3 months
11. Receipt of oral cholera vaccine in the past three years
12. Any potential subject currently participating or who will participate within the next six months in another clinical trial
13. Positive screening urine pregnancy test for females greater than 12 years of age