Randomisation
Eligible participants were randomised 1:1 to one of the two sequences (VP or PV) by a central trial pharmacist using a secure trial database. The randomised study medication was couriered to the participant’s nominated address by the central trial pharmacy. Randomisation lists were prepared by the trial statistician, using permuted block randomisation with variable block sizes (2 or 4) and stratified by recruiting region and self-reported ethnicity (Māori and Pacific vs non-Māori/non-Pacific, including New Zealand European, other European, Indian, Asian, and other groups). This was an open-label trial, where both participants and research staff were aware of the treatment sequences [VP/PV] after randomisation.