HPV vaccination was introduced in Sweden in 2006. Subsidised opportunistic, school-based and catch-up vaccination regimens were successively implemented for different age groups since May 2007. To pursue high vaccination coverage and equal opportunities for prevention of disease, it is key to understand how the uptake of HPV vaccination is distributed among different strata of the population. Therefore we compared demographic and socio-economic factors among parents to their daughter’s HPV vaccination status across different vaccination regimens.
The study cohort comprised 709,427 girls born between May 1990 and March 2003 and ever resident in Sweden between May 1, 2007 and March 18, 2014. HPV vaccination records were retrieved from Prescribed Drug Register and National Vaccination Register. Their biological or foster parents were identified through the National Multi-generation Register, and parents’ country of birth was retrieved from Total Population Register. Parents’ education level and yearly income was retrieved from the Longitudinal Integration Database for Health Insurance and Labour Market Studies. We used Cox regression models to investigate the associations between parents’ country of birth, education, income and their daughter’s HPV vaccine uptake, stratified by vaccination regimens.
The vaccination coverage was around 40%, 45% and 81% for subsidised opportunistic, catch-up and school-based vaccination, respectively. In subsidised vaccination lower participation was seen for girls to mothers who were born outside of Nordic countries (HR:0.42, 95%CI:0.42-0.43), had lower education level (HR:0.47, 95%CI:0.46-0.48) and lower income (HR:0.78, 95%CI:0.77-0.79). In catch-up vaccination, associations with mothers’ country of birth (HR: 0.62, 95%CI:0.60-0.63), education (HR: 0.73, 95%CI:0.71-0.75) and income (HR: 0.89, 95%CI:0.88-0.91) were significantly reduced and in school-based vaccination, the corresponding associations for mother’s country of birth and education were even less salient (HR:0.79, 95%CI:0.78-0.80; HR:0.90, 95%CI:0.88-0.92, respectively), while income remained at about the same level (HR:0.91, 95%CI:0.90-0.93). The corresponding figures associated with the fathers were similar to the above.
The school-based HPV vaccination achieved a high coverage with little variation in demographic and socio-economic disparities, compared to the catch-up and subsidised opportunistic vaccination. A school-based HPV vaccination is most effective to reach high vaccination coverage throughout the whole population, although further efforts should be put on improving vaccination coverage among girls in immigrated families.