Randomisation and masking
Infants were randomly assigned to one of six study groups (1:1:1:1:1:1) through block randomisation (block size of 30) to receive a single dose of PCV10 or PCV13 at 6 weeks of age with a booster at 9 months of age (6-week 1 + 1 group), at 14 weeks of age with a booster at 9 months of age (14-week 1 + 1 group), or two doses at 6 weeks and 14 weeks of age with a booster at 9 months of age (2 + 1 group; days 270 ± 14) in all groups (