Quiambao 2003.

Methods	The study was a randomized, controlled trial.
Participants	Country: Philippines. Number: 106 women in the intervention group and 54 women in the control group. Mean age: 26.8 years. Mean gestational age: 27.3 weeks.
Interventions	23‐valent pneumococcal polysaccharide vaccine.
Outcomes	Neonatal antibody levels (GM).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Details were not reported.
Allocation concealment (selection bias)	Unclear risk	Details were not reported.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Lack of blinding would be unlikely to affect results.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Lack of blinding would be unlikely to affect results.
Incomplete outcome data (attrition bias) All outcomes	High risk	Cord blood was obtained from 42/54 in the control group and 82/106 in the intervention group.
Selective reporting (reporting bias)	Low risk	All outcomes were predefined and reported.
Other bias	Low risk	The trial appears to be free of industry sponsorship.