Zaman 2008.

Methods	The study was a prospective, controlled, blinded, randomized trial.
Participants	Country: Bangladesh. Number: 168 women in the intervention group and 172 women in the control group. Mean age: 24.9 years. Mean gestational age: data not available.
Interventions	23‐valent pneumococcal polysaccharide vaccine vs influenza vaccine.
Outcomes	Incidence of neonatal influenza. Incidence of maternal influenza. Percentage of mothers with seroprotection.
Notes	The main purpose of the trial was to assess the effectiveness of influenza vaccine.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The randomization sequence was computer‐generated.
Allocation concealment (selection bias)	Low risk	The randomization sequentially numbered opaque envelopes with data regarding assignments to study groups were provided to each clinic.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: “double blind”.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: “double blind”.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Of the mother–infant pairs, 316 were observed for the full 24‐week period.
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 and the conflict of interest was declared.

GM: geometric mean
 vs: versus