Safety and Immunogenicity of a New Formulation of a Bivalent Killed, Whole-Cell Oral Cholera Vaccine
Safety and Immunogenicity of a New Formulation of a Bivalent Killed, Whole-Cell Oral Cholera Vaccine
The purpose of this study is to evaluate the safety and immunogenicity of a new formulation
 of a locally-produced bivalent, (O-1 and O-139) killed whole cell oral cholera vaccine among
 Vietnamese adults.
Cholera remains to be a serious public health problem worldwide. In the mid-1980s following
 technology transfer from Sweden, Vietnamese scientists developed and produced an oral killed
 monovalent cholera vaccine for Vietnam's public health programs. A 2-dose regimen of this
 vaccine has been shown to be safe and efficacious. Subsequently, a bivalent vaccine was
 developed containing the newly emergent O139 V. cholerae. This vaccine has several advantages
 over the existing Swedish vaccine. It confers protection against the El Tor biotype in
 younger children, is considerably less expensive, does not require a buffer during
 administration and does not require strict cold chain requirements. However, this vaccine is
 not licensed for use in countries other than Vietnam. In order to make this vaccine available
 to other countries, the IVI has provided technical assistance to produce this vaccine
 following the WHO Good Manufacturing Practices standards. A new formulation of the current
 oral cholera vaccine was produced following these guidelines. Since this vaccine is slightly
 different from the previous vaccine, a study is necessary to demonstrate safety and
 immunogenicity for local licensure and larger Phase III studies in other countries.
Inclusion Criteria:

 -  Healthy non-pregnant adults

 -  Available in the study area for 1 month

 Exclusion Criteria:

 -  Diarrhea for the past week

 -  Antibiotic use in the past week

 -  Intake of anti-diarrheal medicines in the past week

 -  One or more episodes of diarrhea or abdominal pain lasting for 2 weeks during the past
 6 months

 -  Abdominal pain, nausea, vomiting, loss of appetite or generalized ill feeling for the
 past 24 hours

 -  Pregnancy