1. University of Sydney Medical School, Canterbury Hospital; St. Leonards New South Wales Australia
2. Department of Paediatric Otolaryngology; Children's Hospital at Westmead, University of Sydney; Westmead New South Wales Australia
3. Wellington Hospital; Wellington New Zealand
4. Departments of Surgery and Paediatrics; University of Newcastle; New Lambton New South Wales Australia
5. Head, Ear, Nose, and Throat Department, Sydney Children's Hospital; Randwick New South Wales Australia
6. National HPV Vaccination Program Register; East Melbourne Victoria Australia
7. School of Population and Global Health; University of Melbourne; Parkville Victoria Australia