{
  "abstract": "Background: HPV vaccination began in Ireland in 2010, offering Gardasil-4 to girls in first year senior school (age 11-14). At that time, girls up to 6th year in school (age 17-18) were offered vaccination. Gardasil-9 and gender-neutral vaccination were introduced in 2019 (age 11-14) with “catch-up” vaccination offered to girls up to 26 years.\n\nMethods: HPV vaccination data was matched by individual identifiers with cervical screening data on women screened for the first time at age ≥25 during 2020-2024 (n = 74,847). HPV positivity and high-grade cytology rates were compared in participants who received the quadrivalent (Gardasil-4 2010-2019) vs nonavalent vaccines (Gardasil-9 2020-2023) and those aged 11- 14 years vs ≥ 15 years at vaccination.\n\nResults: 99.7% received Gardasil-4 with 43,256/74,847 (57.9%) aged 11-14 at vaccination; remainder aged ≥15. The mean age at first screening was 25.85 years (range 25-35; 95% were 25-29). 17,902/74,847 (23.9%) were HPV positive and had reflex cytology performed. The prevalence of high-grade cytology in the screened population was 776/74,847 (1.04%). Cohorts vaccinated ≥15 years had higher rates of high-grade cytology than those vaccinated prior to age 15 (1.20% vs 0.92%; p < 0.001). Association between older age at vaccination and higher rates of high-grade cytology persisted after adjustment for vaccine type (p<.001). On univariate analysis, cohorts vaccinated at the younger age had higher HPV positive rates (24.2% vs 23.5%; p = 0.039) but this did not persist after vaccine type adjustment. Odds of high-grade were 25% lower in younger girls.\n\nConclusions: This is the first direct evidence of the benefit of HPV vaccination at the optimum age in Ireland; optimal age at vaccination was associated with lower rates of high-grade cytology at first screening. Small numbers received Gardasil-9; while girls vaccinated at a younger age had higher HPV positivity rates, a reduction is anticipated once Gardasil-9 vaccinated cohorts are screened.\n\nKey messages: • This is the first direct evidence of the benefit of HPV vaccination at the optimum age in Ireland.\n\n• Odds of high-grade cytology at first screening were reduced by 25% in those vaccinated at the optimal age (11-14 years).",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "abstract",
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "name": "PE Fitzpatrick"
    },
    {
      "name": "M Rourke"
    },
    {
      "name": "T Mooney"
    },
    {
      "name": "L Jessop"
    },
    {
      "name": "Q Le Cornu"
    },
    {
      "name": "C Martin"
    },
    {
      "name": "C Mason Mohan"
    },
    {
      "name": "L Heavey"
    },
    {
      "name": "MJ Biggs"
    },
    {
      "name": "NE Russell"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6bn17g8ph46zv.bib",
  "cited_by": 0,
  "doi": "10.1093/eurpub/ckag169.1436",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13699860/",
  "id": "6bn17g8ph46zv",
  "issns": [
    "1101-1262",
    "1464-360X"
  ],
  "landing_url": "https://doi.org/10.1093/eurpub/ckag169.1436",
  "language": "en",
  "licence": "CC-BY-NC-4.0",
  "licence_label": "CC BY-NC 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "6. Poster Displays"
    ],
    [
      "heading",
      "AcademicSubjects/MED00860"
    ],
    [
      "heading",
      "AcademicSubjects/SOC01210"
    ],
    [
      "heading",
      "AcademicSubjects/SOC02610"
    ],
    [
      "heading",
      "DL. Health promotion: investing in health and equity"
    ],
    [
      "openalex",
      "2713|Cervical Cancer and HPV Research"
    ]
  ],
  "openalex": "W7223710548",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13699860/pdf/?tool=EBI",
  "pmcid": "PMC13699860",
  "pmid": null,
  "published": "2026-10-01",
  "publisher": "Oxford University Press",
  "ris": "https://research.draconitic.com/paper/6bn17g8ph46zv.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:24Z",
      "native_id": "PMC13699860",
      "source": "pmc",
      "url": "https://doi.org/10.1093/eurpub/ckag169.1436"
    },
    {
      "first_seen": "2026-10-30T12:21:31Z",
      "native_id": "PMC:PMC13699860",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13699860"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2713|Cervical Cancer and HPV Research",
      "subfield": "epidemiology-public-health"
    }
  ],
  "title": "Optimal timing of HPV vaccination reduces high grade cytology at first cervical screening test",
  "title_text": "Optimal timing of HPV vaccination reduces high grade cytology at first cervical screening test",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:36:22Z",
  "url": "https://research.draconitic.com/paper/6bn17g8ph46zv",
  "venue": "The European Journal of Public Health",
  "versions": []
}