School-based vaccination program against HPV and Hepatitis B: A longitudinal analysis of vaccine coverage between 2015 and 2021 in Quebec

Abstract

Background: HPV vaccination prevents cancers, including 90% of cervical cancer. Since 2008, a school-based HPV vaccination program has been implemented in Quebec, but vaccine coverage is suboptimal. The COVID-19 pandemic disrupted school-based vaccination programs. This study aimed to assess variation in HPV vaccination coverage in the school-based program between 2015 and 2022 in Quebec and to identify sociodemographic characteristics associated with non-vaccination.

Methods: HPV vaccine coverage data were extracted from the Quebec Immunization Registry for students in Grade 4 and matched to the 2016 Canadian census sociodemographic data. Descriptive analysis was conducted to explore individual-level vaccine coverage according to sociodemographic data. A Generalized Estimating Equations model assessed the independent association between non-vaccination and students' sociodemographic characteristics.

Results: HPV vaccine coverage (at least one dose) was 84% in 2018-2019 and 85% in 2019-2020. A decrease was observed during the pandemic. In 2020-2021, the HPV vaccine coverage (at least one dose) was 52% (at the end of the school year) and rose to 84% with intense catch-up activities. In 2021-2022, the coverage was slightly lower than before the pandemic (81%). Factors in the dissemination area were statistically significantly associated with non-vaccination: material (p-value = 0.0001) and social deprivation index (p-value = 0.0048), the proportion of immigration (p-value < 0.0001), and the language spoken at home (English (p-value = 0.0318), other than French or English (p-value = 0.0001).

Conclusion: School-based vaccination programs offer equitable access to vaccination, and our analysis showed that some groups have consistently lower vaccine acceptance and uptake. Strategies to improve HPV vaccine coverage should target children living in areas with a higher proportion of immigrants, non-French speakers, and people from underprivileged backgrounds. Although it is too early to assess the full impact of COVID-19 on school-based programs in Quebec, it remains important to ensure that catch-up strategies are implemented for missed doses.

Keywords: COVID-19; HPV infections; HPV vaccine; Immunization; SARS-COV-2; School-based immunization program; Vaccine coverage; Vaccine equity.