Lagos 1999.

Study characteristics
Methods	Design: Randomized controlled trial (individually randomized) Trial dates and duration: June 1995 to Nov 1997; follow‐up 28 days
Participants	Sample size: 312 enrolled Inclusion criteria: Age 3 to 17 months, normal medical history, parental consent Exclusion criteria: Signs and symptoms of acute illness, antibiotic therapy or diarrhoea in previous 2 days
Interventions	Vaccine: CVD 103‐HgR live attenuated vaccine containing: 5 x 109 CFU of lyophilized organisms of a genetically modified V. cholerae O1 Placebo: 5 x 108 CFU of heat‐killed E. coli K12 strain Participants were initially randomized to receive vaccine or placebo. After 14 days all participants in both groups received a dose of vaccine
Outcomes	Included in review: Adverse events during first 7 days after first vaccination (daily home visit and symptom enquiry), Not included in the review: Immunological outcome: Geometric mean serum vibriocidal antibody titres, and IgG antitoxin pre and post dose, proportion who develop ≥4 fold rises in serum titres, Excretion of vaccine strain.
Notes	Location: Santiago, Chile Setting: Well‐baby clinics at a semi‐rural ambulatory health centre. Source of funding: The World Health Organization and NIAID
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: 'For the first dose one‐half were randomly allocated in double blind fashion to receive a dose of vaccine'
Allocation concealment (selection bias)	Low risk	Quote: 'The sachets of test product were packed as individual treatments consisting of two sachets labeled with the same number followed by the letter A or B, indicating the appropriate sachet for the first and second dose of the immunization regimen', 'Each subject received the treatment number matching his/her study identification number'.
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	Comment: Described as 'double‐blind'.
Incomplete outcome data (attrition bias) Efficacy outcomes	Unclear risk	Not applicable as efficacy not reported
Incomplete outcome data (attrition bias) Safety outcomes	Unclear risk	Comment: All randomised participants completed the follow‐up for adverse events following the first dose
Selective reporting (reporting bias)	Low risk	No evidence of selective reporting
Other bias	Low risk	No evidence of other bias