Investigating Canadian parents' HPV vaccine knowledge, attitudes and behaviour: a study protocol for a longitudinal national online survey.

The study received research ethics board approval from the Research Review Office, Integrated Health and Social Services University Network for West-Central Montreal (CODIM-FLP-16-219). The study will adopt a multimodal approach to disseminate the study's findings to researchers, clinicians, cancer and immunisation organisations and the public in Canada and internationally.