“The only vaccine that we really question is the new vaccine”: A qualitative exploration of the social and behavioural drivers of human papillomavirus (HPV) vaccination in Tonga

Human papillomavirus (HPV) vaccination is crucial for cervical cancer elimination, particularly in the Pacific where screening and treatment are limited. The HPV vaccine was introduced through schools in Tonga in November 2022 for adolescent girls. Despite high routine childhood vaccine coverage in Tonga, uptake of the HPV vaccine has been slow. This study explored the social and behavioural drivers of HPV and routine childhood vaccination in Tonga to inform tailored strategies to increase vaccine uptake. We conducted qualitative interviews and focus groups in Nuku'alofa between June and October 2023 with parents (n = 32), adolescent girls (n = 24), teachers (n = 15), nurses (n = 7), and immunization staff (n = 5). Data were analysed thematically and mapped to the World Health Organization's Behavioural and Social Drivers of vaccination framework. Parents, teachers, and girls had limited knowledge of the HPV vaccine. Some feared it would encourage promiscuity or impact fertility. While trust in routine childhood vaccines was high, participants felt the COVID-19 pandemic had reduced confidence in new vaccines. Some vaccinated girls felt the HPV vaccine offered protection whereas others were afraid of side effects. Practical barriers included non-standardised consent forms that had to be returned to schools, the vaccine rollout timing, and school participation. Providing youth, parents and teachers with accurate, culturally appropriate information and supporting teachers to discuss vaccination and facilitate consent may improve HPV vaccine uptake in Tonga.