Randomisation and masking
Participants were randomly assigned to one of five groups in a 4:4:4:4:9 allocation ratio. The first 200 participants per intervention group were further randomised to one of four subgroups and contribute to the immunology substudy, along with a randomly selected 200 of the first 450 participants from the control group. The randomisation was done by a database manager in Australia using a computer-generated list in a block-randomisation scheme (block size 25) stratified by city district. The group (and subgroup) allocation was contained within sealed envelopes at the study clinics, and participants were allocated by a study doctor using the next available envelope. All laboratory-based outcome assessors were masked to the group allocation but participants and those administering vaccines were not.