Simasathien 1994.

Methods	Study design: placebo‐controlled (for both Enhanced IPV and OPV), randomised trial Setting: Phramongkutkloa Hospital, Bangkok, Thailand The study was conducted as part of a trial of an oral rhesus‐human reassortant rotavirus tetravalent vaccine (RRV‐TV) given together with OPV. Enhanced potency inactivated poliovirus vaccine, combined with diphtheria‐tetanus‐pertussis (DTP) vaccine, was compared with oral poliovirus vaccine (OPV) regarding immunogenicity in Thai infants, vaccinated at 2, 4 and 6 months of age. Study dates: not reported
Participants	Sample size: 330 Dropouts/withdrawals: not reported Age: 2 months at entry Sex: not reported Inclusion criteria: healthy full‐term ( 2 37 weeks of gestation) infants with birth weight of ≥ 2500 g were recruited for the study at birth. Exclusion criteria: not reported
Interventions	Group A (n = 110): OOOO at 2, 4, 6, 9 months (no RRV‐TV) Group B (n = 110): OOOO at 2, 4, 6, 9 months + RRV‐TV Group C (n = 110): IIIO at 2, 4, 6, 9 months + RRV‐TV OPV (or the respective placebo) was given first in 2 drops. Parenteral immunization (DTP plus placebo or DTP plus EIPV) was given after the oral vaccination. A standard lot of oral poliovirus vaccine (OPV), prepared by SmithKline Beecham Biologicals (Rixensart, Belgium) for studies with the WHO Expanded Programme on Immunization (EPI), was donated by the manufacturer for the study. The vaccine was of the 10: 1 : 3 type, and contained the following amounts of vaccine viruses: serotype 1, 106 TCID50 serotype 2, 105 TCID50and serotype 3, 105 TCID50. EIPV lot number 311, prepared by the Dutch National Institute of Public Health and Environmental Protection (RIVM. Bilthoven, The Netherlands) was used. The EIPV contained 40 D‐antigen units (12) of serotype I, 8 DU of serotype 2, and 32 DU of serotype 3.
Outcomes	Poliovirus antibody responses in groups (A) and (C) at 12 months. Timing of outcome assessment: 12 months. Follow‐up: 10 months
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "The randomization was done by World Health Organization in Geneva..." Comment: not described
Allocation concealment (selection bias)	Low risk	Quote: "The randomization was done by WHO in Geneva, and the manufacturers were requested to code their vaccines accordingly. The code was held in Geneva and was not made available to the investigators until completion of the study."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: placebo‐controlled trial
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: probably blinded. Additionally, the objective outcome (antibody titres) is not likely to be influenced by lack of blinding.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: 15% of patients were unavailable for serology at 12 months
Selective reporting (reporting bias)	Low risk	Comment: no evidence of selecting reporting
Other bias	Low risk	Comment: no evidence of other bias
Conflict of interest	Low risk	Comment: the study was financially supported by the Diarrhoea Diseases Control Programme, WHO.