Human papillomavirus (HPV) vaccine coverage and associated sociodemographic factors among individuals eligible for publicly funded vaccine in Ontario, Canada from 2007 to 2023: a Canadian immunization research network study

Background — Publicly funded human papillomavirus (HPV) vaccination programs are available for school-aged children to help prevent HPV-associated cancers and other outcomes, with goals of reaching 90% coverage (≥2 doses) in Canada. Since the introduction of gender-neutral programs in Ontario (2016/2017), publicly available coverage estimates by sex and other sociodemographics, particularly throughout the COVID-19 pandemic, have been limited.

Methods — We conducted a population-based cohort study consisting of males and females eligible for publicly funded HPV vaccine programs in Ontario (2007-2023). Using linked vaccination and administrative databases, we estimated vaccine coverage by sex, year, birth cohort, and various sociodemographics. We explored the impacts of the COVID-19 pandemic on coverage by comparing those who first became eligible during pandemic years to those who first became eligible before the pandemic. Multinomial logistic regression was used to report on associations between sociodemographics and vaccination status (unvaccinated, partial vaccination, up-to-date [≥2 doses] vaccination).

Results — Up-to-date coverage varied by birth cohort and sex, ranging from 40-70% among females and 40-66% among males; uptake of at least 1 dose was higher (females:51-77%; males:60-74%). The lowest coverage estimates were among individuals who first became program eligible during the pandemic with some improvement in coverage through catch-up opportunities in later years (i.e., from 3-6% [2019-2021] to 40-51% [2022-2023]). Vaccine coverage, particularly up-to-date vaccination, was associated with socioeconomic status, with individuals in the lowest income neighbourhoods experiencing lower uptake, for example. This trend was most apparent among cohorts who became eligible during pandemic years.

Conclusions — Following inception of gender-neutral publicly funded programs in Ontario, HPV vaccine coverage for females and males has been substantially short of national goals. Findings suggest a need to improve uptake and access to publicly funded catch-up opportunities. Efforts to reduce inequities in vaccine uptake are crucial to reach targets and close the gap in HPV-associated disparities.