Hong Kong trial (ph3,2v).

Methods	Phase III, double‐blind, randomised controlled trial
Participants	294 women (148 in the vaccine arm and 146 in the placebo arm) from Hong Kong Age range: women aged 18 to 35 years. Inclusion criteria: women who were healthy Exclusion criteria: women who were receiving any investigational or non‐registered drug or vaccine, those who had received AS04‐adjuvant or HPV vaccine, those having a chronic disease or were pregnant, breastfeeding or planning to conceive were excluded
Interventions	Vaccine: HPV16/18 AS04‐adjuvant bivalent vaccine Placebo: visually indistinguishable aluminium‐containing placebo
Outcomes	Safety and immunogenicity
Notes	Last report average follow‐up time: 7 months (Hong Kong trial (ph3,2v))
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Women were randomised in a 1:1 ratio with an Internet‐based centralised randomisation system
Allocation concealment (selection bias)	Low risk	A single treatment number was used for each patient uniquely identify the doses administered to the participant
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not described in the paper
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described in the paper
Incomplete outcome data (attrition bias) All outcomes	Low risk	All outcomes (safety and immunogenicity) were reported on the total vaccinated cohort. Reason for exclusion was noted and balanced between vaccine group and placebo group
Selective reporting (reporting bias)	Low risk	All outcomes (safety and immunogenicity) were presented