Trends in Routine First-Dose Human Papillomavirus Vaccination Coverage in Wakayama Prefecture, Japan, Fiscal Years 2020–2025

Abstract Background In Japan, proactive recommendations for human papillomavirus vaccination were suspended in 2013 and resumed in fiscal year 2022 alongside a catch-up program, whose first-dose eligibility ended in fiscal year 2024. Coverage among subsequent routine-vaccination cohorts remains unclear. We described first-dose vaccination coverage in Wakayama Prefecture during fiscal years 2020–2025, focusing on grade-specific differences between 2024 and 2025. Methods This descriptive epidemiological study used aggregated administrative data. Age-specific first-dose counts were obtained from e-Stat for fiscal years 2020–2021 and the Wakayama Prefectural Government for 2022–2025. Denominators were age-specific female populations from the 2020 Population Census. Vaccination counts and population data were reconstructed by birth fiscal year using a published method. Annual and cumulative coverage were estimated for the 2004–2013 birth cohorts. Results Between fiscal years 2024 and 2025, annual coverage changed from 3.8% to 4.1% in sixth-grade elementary school students, 20.6% to 15.4% in first-year junior high school students, 2.2% to 7.7% in second-year junior high school students, 30.5% to 16.4% in third-year junior high school students, and 13.1% to 6.1% in first-year high school students. Cumulative coverage by the end of first-year high school was 46.5% and 49.9% for the 2008 and 2009 birth cohorts, respectively. The highest-coverage grade shifted from first-year high school to third-year junior high school. Conclusions The predominant timing of first-dose vaccination shifted toward younger grades during fiscal years 2020–2025. However, annual coverage in 2025 was lower than in 2024 among first- and third-year junior high school students and first-year high school students.