• adverse events [ Time Frame: immediate events - 30 minutes after each dose, adverse events - for 3 days following dose, serious adverse events throughout study - 28 days ] [ Designated as safety issue: Yes ]
  

• serum vibriocidal antibody response [ Time Frame: baseline and 14 days after second dose ] [ Designated as safety issue: No ]
  

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.

Through IVI, an agreement between VABIOTECH in Hanoi and Shantha Biotechnics PVT, LTD in India has been reached that will make the bivalent vaccine available in India. A double-blind randomized phase III trial in a cholera-endemic area would be necessary to demonstrate the efficacy of this vaccine in other settings. This would pave the way for the introduction of the vaccine into the national immunization programme in India and the internationalization of this vaccine and licensure in other countries where it is needed. Prior to the phase III trial, a phase II study will be performed among adults and children.