{
  "abstract": "The rapid development of effective COVID-19 vaccines was enabled by the parallel assessment of multiple candidates early in the pandemic, including candidates based on the Modified Vaccinia virus Ankara (MVA) vector platform. This Phase 1 trial (NCT04569383) evaluated the MVA-based vaccine candidate MVA-SARS-2-S, expressing the full-length native SARS-CoV-2 spike glycoprotein (Wuhan-HU-1). Between October 2020 and May 2021, 30 healthy, SARS-CoV-2-naive adults received two doses of either 10⁷ or 10⁸ international units (IU) of MVA-SARS-2-S 28 days apart, with 6-month follow-up. A subgroup (n = 12) received two BNT162b2 booster vaccinations. Safety and reactogenicity were primary objectives; secondary and exploratory objectives included S1 seroconversion rates, S-domain-specific antibodies, SARS-CoV-2-neutralizing antibodies, and spike-specific T cell responses. MVA-SARS-2-S demonstrated a good safety profile. No severe or serious adverse events occurred. Immunogenicity was poor: S1-specific seroconversion occurred in 0/15 (10⁷ IU group) and 3/15 (10⁸ IU group) participants. Binding antibodies were predominantly directed against the S2 subunit, with peak median anti-S2 fold changes of 6.0 and 5.2 in the 10⁷ IU and 10⁸ IU groups, respectively. Neutralizing antibodies were detected in one participant (10⁸ IU group); spike-specific T cell responses were observed in 5/15 (10⁷ IU group) and 2/13 (10⁸ IU group) participants. Heterologous BNT162b2 vaccination induced S1 seroconversion and detectable neutralizing antibody and T cell responses in all boosted participants, without safety concerns. In conclusion, while MVA-SARS-2-S was well tolerated and did not adversely affect subsequent BNT162b2 boosting, the vaccine candidate elicited insufficient immunogenicity, underscoring the need for optimized antigen design.",
  "abstract_shown": true,
  "affiliations": [
    "University Medical Centre Hamburg-Eppendorf, Institute for Infection Research and Vaccine Development (IIRVD), Hamburg, Germany.",
    "Bernhard-Nocht-Institute for Tropical Medicine, Department for Clinical Immunology of Infectious Diseases, Hamburg, Germany.",
    "German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, Germany.",
    "University Medical Centre Hamburg-Eppendorf, First Department of Medicine, Division of Infectious Diseases, Hamburg, Germany.",
    "German Center for Infection Research, Partner Site Bonn-Cologne, Germany.",
    "University of Cologne, Faculty of Medicine and University Hospital of Cologne, Department I of Internal Medicine, Centre for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Cologne, Germany.",
    "University of Cologne, Faculty of Medicine and University Hospital Cologne, Chair Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany.",
    "German Center for Infection Research, Partner Site Gießen-Marburg-Langen, Germany.",
    "Philipps-Universität Marburg, Fachbereich Medizin, Institut für Virologie, Marburg, Germany.",
    "German Center for Infection Research, Partner Site Tübingen, Germany.",
    "Institute of Tropical Medicine; Tübingen, University of Tübingen, Germany.",
    "Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.",
    "University Medical Centre Hamburg-Eppendorf, Institute of Medical Microbiology, Virology, and Hygiene, Hamburg, Germany.",
    "German Center for Infection Research, Partner Site Munich, Germany.",
    "LMU University of Munich, Institute of Infectious Diseases and Zoonoses, Munich, Germany."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 18,
  "authors": [
    {
      "affs": [
        0,
        1,
        2,
        3
      ],
      "name": "Anahita Fathi",
      "orcid": "0000-0002-9351-9471"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Christine Dahlke"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Leonie Mayer"
    },
    {
      "affs": [
        0,
        1,
        4,
        5,
        6
      ],
      "name": "Sibylle C Mellinghoff"
    },
    {
      "affs": [
        7,
        8
      ],
      "name": "Verena Krähling"
    },
    {
      "affs": [
        7,
        8
      ],
      "name": "Sandro Halwe"
    },
    {
      "affs": [
        8
      ],
      "name": "Helena Müller-Kräuter"
    },
    {
      "affs": [
        9,
        10,
        11
      ],
      "name": "Rolf Fendel"
    },
    {
      "affs": [
        9,
        10,
        11
      ],
      "name": "Peter Kremsner"
    },
    {
      "affs": [
        9,
        10,
        11
      ],
      "name": "Meral Esen"
    },
    {
      "affs": [
        9,
        10
      ],
      "name": "Martha Klug"
    },
    {
      "affs": [
        2,
        12
      ],
      "name": "Marc Lütgehetmann"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Leonie M Weskamm"
    },
    {
      "name": "MVA-SARS-2-S Study Group"
    },
    {
      "affs": [
        13,
        14
      ],
      "name": "Gerd Sutter"
    },
    {
      "affs": [
        7,
        8
      ],
      "name": "Stephan Becker"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Svenja Hardtke"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Marylyn M Addo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0f4j17ncnwcm6.bib",
  "cited_by": 0,
  "doi": "10.1080/21645515.2026.2728535",
  "fulltext_url": "https://europepmc.org/articles/PMC13679322",
  "id": "0f4j17ncnwcm6",
  "issns": [
    "2164-5515",
    "2164-554X"
  ],
  "landing_url": "https://europepmc.org/article/MED/42878689",
  "language": "eng",
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2725|SARS-CoV-2 and COVID-19 Research"
    ]
  ],
  "openalex": "W7222301843",
  "pdf_url": "https://europepmc.org/articles/PMC13679322?pdf=render",
  "pmcid": "PMC13679322",
  "pmid": "42878689",
  "published": "2026-10-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0f4j17ncnwcm6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:46Z",
      "native_id": "MED:42878689",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42878689"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2725|SARS-CoV-2 and COVID-19 Research",
      "subfield": "infectious-disease"
    }
  ],
  "title": "Safety and immunogenicity of a first-generation modified vaccinia virus Ankara-vectored SARS-CoV-2 vaccine candidate with mRNA-based booster vaccination: A phase 1 trial.",
  "title_text": "Safety and immunogenicity of a first-generation modified vaccinia virus Ankara-vectored SARS-CoV-2 vaccine candidate with mRNA-based booster vaccination: A phase 1 trial.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:46Z",
  "url": "https://research.draconitic.com/paper/0f4j17ncnwcm6",
  "venue": "Human vaccines & immunotherapeutics",
  "versions": []
}