{
  "abstract": "BackgroundIn 2025, COVID-19 vaccination programmes in England targeted adults aged [≥]75 years and immunosuppressed individuals, with JN.1-based vaccines offered in spring and KP.2-based vaccines offered in autumn. This study evaluated vaccine effectiveness (VE) against COVID-19 hospitalisation following these campaigns and assessed VE in immunosuppressed populations.\n\nMethodsVE against COVID-19 hospitalisation in adults aged [≥]75 years following the 2025 spring JN.1 and autumn KP.2 vaccination campaigns was estimated using a test-negative case-control design. Logistic regression was used to calculate VE among eligible hospitalised individuals, adjusting for covariates. Manufacturer-specific analyses were performed for the spring 2025 campaign. VE in immunosuppressed and non-immunosuppressed adults aged [≥]75 years was assessed by pooling estimates from the autumn 2024 and spring and autumn 2025 campaigns using fixed-effects meta-analysis.\n\nResultsSpring 2025 JN.1 vaccines conferred moderate protection, peaking at 55% (95%CI: 45-62%) within 5-9 weeks and declining to 17% (95%CI: -18-42%) from 35 weeks onwards. Autumn 2025 KP.2 VE peaked at 48% (95%CI: 34-59%) at 5-9 weeks, with follow-up needed to assess long-term protection. No significant differences were observed between manufacturers in the spring campaign. VE following autumn KP.2 vaccination was lower among individuals who received a spring JN.1 vaccine. When assessed across three campaigns, there was some evidence that VE was lower in individuals with immunosuppression than those without.\n\nConclusionThe 2025 COVID-19 vaccination programmes in England provided moderate protection against COVID-19 hospitalisation in adults aged [≥]75 years, with protection waning over time. The findings support the continued benefit of seasonal vaccination in high-risk groups, including immunosuppressed individuals.",
  "abstract_shown": true,
  "affiliations": [
    "UK Health Security Agency"
  ],
  "article_type": "PUBLISHAHEADOFPRINT",
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "N. Abdul Aziz"
    },
    {
      "name": "A. Allen"
    },
    {
      "name": "N. Andrews"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/14w5ze5knhw8s.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.14.26362989",
  "fulltext_url": "https://www.medrxiv.org/content/10.64898/2026.09.14.26362989v1.full",
  "id": "14w5ze5knhw8s",
  "issns": [],
  "landing_url": "https://www.medrxiv.org/content/10.64898/2026.09.14.26362989v1",
  "language": null,
  "licence": "CC-BY-ND",
  "licence_label": "CC BY-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "medrxiv",
      "epidemiology"
    ],
    [
      "openalex",
      "2725|SARS-CoV-2 and COVID-19 Research"
    ]
  ],
  "openalex": "W7213281584",
  "pdf_url": "https://www.medrxiv.org/content/10.64898/2026.09.14.26362989v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-14",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/14w5ze5knhw8s.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:39Z",
      "native_id": "10.64898/2026.09.14.26362989",
      "source": "medrxiv",
      "url": "https://www.medrxiv.org/content/10.64898/2026.09.14.26362989v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "medrxiv:epidemiology",
      "subfield": "epidemiology-public-health"
    }
  ],
  "title": "Effectiveness of 2025 bi-annual COVID-19 vaccination campaigns against hospitalisation in England",
  "title_text": "Effectiveness of 2025 bi-annual COVID-19 vaccination campaigns against hospitalisation in England",
  "type": "preprint",
  "updated_at": "2026-10-30T12:18:39Z",
  "url": "https://research.draconitic.com/paper/14w5ze5knhw8s",
  "venue": "medRxiv",
  "versions": []
}