Mahalanabis 2008.

Study characteristics
Methods	Design: Randomized controlled trial (individually randomized) Trial dates and duration: Enrollment from Aug to Oct 2005; follow‐up for 28 days
Participants	Sample size: 201 participants stratified into adults and children Inclusion criteria: Age 18 to 40 years for adult study, 1 to 17 years for children, healthy male and non‐pregnant females, written informed consent Exclusion criteria: Abdominal pain, vomiting, loss of appetite, generalized ill‐feeling or nausea during the preceding 24 hours, diarrhoea or history of anti‐diarrhoeal or antibiotic use during the past week, history of diarrhoea and abdominal pain lasting for more than 2 weeks during the past 6 months
Interventions	Vaccine: Bivalent killed whole‐cell vaccine (BivWC: Shanchol®, Shantha Biotechnics) Placebo: Heat‐killed E. coli K12 strain All subjects were randomized to receive 2 doses, at an interval of 14 days. All doses were administered via an oral syringe and offered water.
Outcomes	No evidence of other bias
Notes	Location: Kolkata, India Setting: Clinical trial ward of the Infectious Diseases Hospital Source of funding: The Bill and Melinda Gates Foundation through the Diseases of Most Impoverished Program administered by the International Vaccine Institute, and the Swedish International Development Cooperation Agency
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: 'Separate randomization lists for adults and children were prepared by a statistician in IVI who was otherwise not involved in the study. Randomization numbers were generated in blocks of 8 using the program Visual Fortran 5.0. (Digital, USA)'.
Allocation concealment (selection bias)	Low risk	Quote: 'Study agents were coded using 8 letters (4 for vaccine and 4 for placebo) in the adult trial and 8 different letters in the pediatric trial. Only the code letters on the vials identified the study agents as vaccine or placebo. The codes were revealed to the researchers once recruitment, data collection, and laboratory analyses were complete'
Blinding (performance bias and detection bias) Efficacy outcomes	Unclear risk	Not applicable as efficacy not reported
Blinding (performance bias and detection bias) Safety outcomes	Low risk	Quote: 'All study personnel and participants were blinded to treatment assignment during the duration of the study'.
Incomplete outcome data (attrition bias) Efficacy outcomes	Unclear risk	Not applicable as efficacy not reported
Incomplete outcome data (attrition bias) Safety outcomes	Low risk	Comment: Three randomized participants (2.5%) were excluded from the adverse event follow‐up, one who declined the first dose and two who received the wrong allocation for the second dose
Selective reporting (reporting bias)	Low risk	No evidence of selective outcome reporting
Other bias	Low risk	No evidence of other bias