Qiu 2017.

Methods	Study design: multi‐centre, open‐label, non‐inferiority RCT Setting: Hezhou County and Zhongshan County, Guangxi Zhuang Autonomous Region of China Study dates: from April 8 and August 23, 2015
Participants	Participants: 600 healthy full‐term (37 to 42 weeks) infants who weighed more than 2.5 kg at birth with no obvious medical disorders, no polio vaccination, no immunoglobulin vaccination, with no other attenuated vaccine administered in the past 14 days and no other inactivated vaccine administered. Sample size: 600 Dropouts/withdrawals: 48 (35 = withdrawn, 5 = adverse event, 3 = protocol deviation, 3 = move, 2 = other) Age: range = 2‐3 months Sex: male = 231, female = 369 Inclusion criteria: "Eligible participants were healthy full‐term (37–42 weeks) infants aged 60–90 days who weighed more than 2.5 kg at birth with no obvious medical disorders, no polio vaccination, no immunoglobulin vaccination, with no other attenuated vaccine administered in the past 14 days and no other inactivated vaccine administered." (quote) Exclusion criteria: "Participants were excluded if meet one or more of the following criteria: had or were at risk of immunodeficiency, severe allergic reaction, acute fever or infectious diseases, severe chronic diseases, family history of allergies, convulsions, seizures, encephalopathy or psychiatric diseases, oral steroids during at least 14 consecutive days of the preceding month,auxiliary temperature equal or greater than 38.0C during the past 3 days, diarrhoea (defection frequency equal or greater than3 times per day) in the past 7 days, and participated in other drug clinical trials." (quote)
Interventions	Group 1 (n = 100): IOO (bOPV) Group 2 (n = 100): IOO (tOPV) Group 3 (n = 100): IIO (bOPV) Group 4 (n = 100): IIO (tOPV) Group 5 (n = 100): III Group 6 (n = 100): OOO (tOPV) Administration: 3 doses administered sequentially at 4 to 6 weeks interval after collecting baseline blood sample
Outcomes	Primaryoutcome Proportion of infants with seroconversion ≥8 times (if pre‐vaccination titre <8) and ≥4 times for other participants 30 days after vaccination. Proportion of infants with serious adverse events 6 months after the vaccination Secondary outcomes Overall seroprotection rate at 30 days after vaccination (defined as the proportion of participants with reciprocal titre ≥8) Geometric mean of antibody titre (GMT) 30 days after vaccination Increase of geometric mean of antibody titre (GMI) 30 days after vaccination Proportion of infants with serious adverse events 6 months after vaccination Solicited adverse events 30 days after vaccination Timing of outcome assessment: 30 days after last vaccination Follow‐up: 5 months
Notes	NCT02785705
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Serial numbers from 1–600 were equally randomized (1:1:1:1:1:1) into 6 sequential vaccination schedules"
Allocation concealment (selection bias)	Low risk	Quote: "Sites were provided with sealed envelopes"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Considering that the formulations are different, the vaccines could not be completely masked (oral vs. injectable), however, the bOPV and tOPV vaccines could be masked" Comment: performance, in terms of intervention or co‐interventions, is not likely to be influenced by lack of blinding
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Laboratory investigators were blinded to group assignments. A statistician would analyze data unblinded with the allocation schedule after the database was locked".
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: overall, 84% analysed per protocol for immunogenicity outcomes, and 95% for safety outcomes
Selective reporting (reporting bias)	Low risk	Comment: the study register is available (NCT02785705) and all of the study’s pre‐specified (primary and secondary) outcomes have been reported in the pre‐specified way.
Other bias	Low risk	Comment: the study appears to be free of other sources of bias.
Conflict of interest	Low risk	Comment: sponsored by Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Fourth Military Medical University, and Beijing Tiantan Biological Products Co, Ltd