{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=High+Dose+Quadrivalent+Influenza+Vaccine",
    "query": {
      "intervention": "High Dose Quadrivalent Influenza Vaccine"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 56,
    "total_pages": 6,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=High+Dose+Quadrivalent+Influenza+Vaccine&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-29T23:11:34.968Z",
  "attribution": "Data derived from public ClinicalTrials.gov records. The official record at https://clinicaltrials.gov/ remains the source of truth for current availability, contacts, and full study details.",
  "notes": [
    "This endpoint exposes only public summary fields — no participant contact emails, phone numbers, or scraped investigator contact details.",
    "For contact information and full protocol detail, follow each trial's `official_url` to the ClinicalTrials.gov record.",
    "This API is a navigational aid. It does not provide medical advice, eligibility determinations, or compensation guarantees."
  ],
  "trials": [
    {
      "nct_id": "NCT04622592",
      "title": "Adjuvanted Seasonal Recombinant Quadrivalent Virus-Like Particles (QVLP) Influenza Vaccine in Adults 65 Years of Age and Older",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Instramuscular vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Medicago",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "65 Years and older"
      },
      "enrollment_count": 209,
      "start_date": "2020-11-02",
      "completion_date": "2022-04-26",
      "has_results": true,
      "last_update_posted_date": "2023-07-21",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 14,
      "location_summary": "Huntsville, Alabama • Chandler, Arizona • San Diego, California + 11 more",
      "locations": [
        {
          "city": "Huntsville",
          "state": "Alabama"
        },
        {
          "city": "Chandler",
          "state": "Arizona"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Melbourne",
          "state": "Florida"
        },
        {
          "city": "Orlando",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04622592"
    },
    {
      "nct_id": "NCT04613206",
      "title": "High vs. Standard Dose Influenza Vaccine in Adult SOT Recipients",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Immunization; Infection",
        "Transplantation Infection",
        "Influenza",
        "Solid Organ Transplant"
      ],
      "interventions": [
        {
          "name": "High Dose Quadrivalent Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Standard Dose Quadrivalent Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Vanderbilt University Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 396,
      "start_date": "2021-01-11",
      "completion_date": "2026-12-31",
      "has_results": false,
      "last_update_posted_date": "2026-01-21",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04613206"
    },
    {
      "nct_id": "NCT03722589",
      "title": "Immunogenicity Trial of Egg- Versus Non-Egg-Based Influenza Vaccines Among HCP",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Flublok",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Flucelvax",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluarix",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone High-Dose",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Centers for Disease Control and Prevention",
      "sponsor_class": "FED",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "65 Years",
        "sex": "ALL",
        "summary": "18 Years to 65 Years"
      },
      "enrollment_count": 944,
      "start_date": "2018-09-12",
      "completion_date": "2020-07-31",
      "has_results": true,
      "last_update_posted_date": "2024-07-22",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 2,
      "location_summary": "Portland, Oregon • Temple, Texas",
      "locations": [
        {
          "city": "Portland",
          "state": "Oregon"
        },
        {
          "city": "Temple",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03722589"
    },
    {
      "nct_id": "NCT05007041",
      "title": "Simultaneous RZV and aIIV4 Vaccination",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Pain",
        "Quality of Life",
        "Injection Site Reaction",
        "Adverse Drug Event"
      ],
      "interventions": [
        {
          "name": "FLUAD® Quadrivalent",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone® High-Dose Quadrivalent",
          "type": "BIOLOGICAL"
        },
        {
          "name": "SHINGRIX®",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Duke University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "65 Years and older"
      },
      "enrollment_count": 267,
      "start_date": "2021-09-21",
      "completion_date": "2023-06-08",
      "has_results": true,
      "last_update_posted_date": "2024-07-11",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 2,
      "location_summary": "Baltimore, Maryland • Durham, North Carolina",
      "locations": [
        {
          "city": "Baltimore",
          "state": "Maryland"
        },
        {
          "city": "Durham",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05007041"
    },
    {
      "nct_id": "NCT04551677",
      "title": "Annual Study for Collection of Serum Samples in Children and Older Adults Receiving the 2020-2021 Formulations of Fluzone Quadrivalent Vaccine and Fluzone High-Dose Quadrivalent Vaccine, Respectively",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Influenza Immunization",
        "Healthy Volunteers"
      ],
      "interventions": [
        {
          "name": "Fluzone Quadrivalent vaccine, No Preservative (0.5-mL dose), 2020-2021 formulation",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone High-Dose Quadrivalent vaccine (0.7-mL dose), 2020-2021 formulation",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Sanofi Pasteur, a Sanofi Company",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "6 Months",
        "maximum_age": "84 Years",
        "sex": "ALL",
        "summary": "6 Months to 84 Years"
      },
      "enrollment_count": 90,
      "start_date": "2020-09-16",
      "completion_date": "2020-12-18",
      "has_results": true,
      "last_update_posted_date": "2025-09-12",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 2,
      "location_summary": "Bardstown, Kentucky • Salt Lake City, Utah",
      "locations": [
        {
          "city": "Bardstown",
          "state": "Kentucky"
        },
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04551677"
    },
    {
      "nct_id": "NCT05215327",
      "title": "High vs. Standard Dose Influenza Vaccine in Lung Allograft Recipients",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Immunization; Infection",
        "Transplantation Infection",
        "Influenza"
      ],
      "interventions": [
        {
          "name": "High Dose Quadrivalent Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Standard Dose Quadrivalent Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Vanderbilt University Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "16 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "16 Years and older"
      },
      "enrollment_count": 270,
      "start_date": "2022-11-08",
      "completion_date": "2027-12-31",
      "has_results": false,
      "last_update_posted_date": "2026-09-04",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05215327"
    },
    {
      "nct_id": "NCT06744205",
      "title": "A Study on the Safety and Immunogenicity of Hexavalent Influenza mRNA Vaccine in Adult Participants 50 Years of Age and Older",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Influenza",
        "Healthy Volunteers"
      ],
      "interventions": [
        {
          "name": "Trivalent (TIV) messenger ribonucleic acid (mRNA) hemagglutinin (HA) Vaccine 1",
          "type": "BIOLOGICAL"
        },
        {
          "name": "TIV mRNA-neuraminidase (NA)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "TIV mRNA-HA Vaccine 2",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Influenza Standard Dose Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Influenza Vaccine High Dose",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Sanofi Pasteur, a Sanofi Company",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "50 Years and older"
      },
      "enrollment_count": 1162,
      "start_date": "2025-01-06",
      "completion_date": "2026-05-22",
      "has_results": false,
      "last_update_posted_date": "2026-06-09",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 21,
      "location_summary": "Birmingham, Alabama • Mobile, Alabama • Tempe, Arizona + 18 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Mobile",
          "state": "Alabama"
        },
        {
          "city": "Tempe",
          "state": "Arizona"
        },
        {
          "city": "Coral Gables",
          "state": "Florida"
        },
        {
          "city": "DeLand",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06744205"
    },
    {
      "nct_id": "NCT03179761",
      "title": "High vs. Standard Dose Flu Vaccine in Adult Stem Cell Transplant Recipients",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Hematopoietic Cell Transplantation"
      ],
      "interventions": [
        {
          "name": "Quadrivalent Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Laboratory Biomarker Analysis",
          "type": "OTHER"
        },
        {
          "name": "Trivalent Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "OTHER"
      ],
      "sponsor": "Vanderbilt-Ingram Cancer Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 124,
      "start_date": "2017-10-09",
      "completion_date": "2024-10-01",
      "has_results": true,
      "last_update_posted_date": "2024-12-04",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 4,
      "location_summary": "Birmingham, Alabama • Chicago, Illinois • Nashville, Tennessee + 1 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        },
        {
          "city": "Seattle",
          "state": "Washington"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03179761"
    },
    {
      "nct_id": "NCT01827462",
      "title": "Comparison of Immune Responses to Influenza Vaccine In Adults of Different Ages (SLVP015 2007-2017)",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Trivalent, inactivated influenza vaccine (TIV)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent, inactivated influenza vaccine (IIV4)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "High-Dose Trivalent, inactivated influenza vaccine (TIV High-Dose)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Stanford University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "100 Years",
        "sex": "ALL",
        "summary": "18 Years to 100 Years"
      },
      "enrollment_count": 136,
      "start_date": "2007-10",
      "completion_date": "2017-03",
      "has_results": true,
      "last_update_posted_date": "2017-07-11",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 1,
      "location_summary": "Stanford, California",
      "locations": [
        {
          "city": "Stanford",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01827462"
    },
    {
      "nct_id": "NCT01946438",
      "title": "Study of Fluzone® Quadrivalent, Fluzone® Intradermal, and Fluzone® High-Dose Influenza Virus Vaccines in Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Fluzone® Quadrivalent, Influenza Virus Vaccine (2013-2014 formulation),",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone® Intradermal, Influenza Virus Vaccine (2013-2014 formulation),",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone® High-Dose, Influenza Virus Vaccine (2013-2014 formulation)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Sanofi Pasteur, a Sanofi Company",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 208,
      "start_date": "2013-09",
      "completion_date": "2014-07",
      "has_results": true,
      "last_update_posted_date": "2014-09-25",
      "last_synced_at": "2026-09-29T23:11:34.968Z",
      "location_count": 4,
      "location_summary": "Santa Rosa, California • Council Bluffs, Iowa • Metairie, Louisiana + 1 more",
      "locations": [
        {
          "city": "Santa Rosa",
          "state": "California"
        },
        {
          "city": "Council Bluffs",
          "state": "Iowa"
        },
        {
          "city": "Metairie",
          "state": "Louisiana"
        },
        {
          "city": "Cincinnati",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01946438"
    }
  ]
}