{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=FLU+HD+vaccine",
    "query": {
      "intervention": "FLU HD vaccine"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 49,
    "total_pages": 5,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=FLU+HD+vaccine&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-26T06:37:00.682Z",
  "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": "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": "2026-09-26T06:37:00.682Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04613206"
    },
    {
      "nct_id": "NCT02872311",
      "title": "Open-Label Influenza Vaccine Evaluation",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Immune Response"
      ],
      "interventions": [
        {
          "name": "High Dose Influenza vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Adjuvanted Influenza vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Standard Dose Influenza vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Recombinant Influenza vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Marshfield Clinic Research Foundation",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": "74 Years",
        "sex": "ALL",
        "summary": "65 Years to 74 Years"
      },
      "enrollment_count": 179,
      "start_date": "2016-09",
      "completion_date": "2018-09",
      "has_results": true,
      "last_update_posted_date": "2025-12-10",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 1,
      "location_summary": "Marshfield, Wisconsin",
      "locations": [
        {
          "city": "Marshfield",
          "state": "Wisconsin"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02872311"
    },
    {
      "nct_id": "NCT04544267",
      "title": "Study on a High-Dose Quadrivalent Influenza Vaccine Compared With Standard-Dose Quadrivalent Influenza Vaccine in Children 6 Months Through 35 Months of Age",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Quadrivalent influenza vaccine, high-dose",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent influenza vaccine, standard dose",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Sanofi Pasteur, a Sanofi Company",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "6 Months",
        "maximum_age": "35 Months",
        "sex": "ALL",
        "summary": "6 Months to 35 Months"
      },
      "enrollment_count": 100,
      "start_date": "2020-09-15",
      "completion_date": "2021-06-02",
      "has_results": true,
      "last_update_posted_date": "2025-12-24",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 10,
      "location_summary": "San Diego, California • Miami, Florida • Atlanta, Georgia + 6 more",
      "locations": [
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Miami",
          "state": "Florida"
        },
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "El Dorado",
          "state": "Kansas"
        },
        {
          "city": "Bardstown",
          "state": "Kentucky"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04544267"
    },
    {
      "nct_id": "NCT01215734",
      "title": "Standard vs High-Dose Trivalent Inactivated Flu Vaccine in Adult Hematopoetic Stem Cell Transplant (HSCT) Recipients",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Adult Stem Cell Hematopoetic Transplant"
      ],
      "interventions": [
        {
          "name": "High-Dose Trivalent Inactivated Influenza Vaccine (HD-TIV)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Standard Dose Trivalent Inactivated Flu Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "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": 44,
      "start_date": "2010-10",
      "completion_date": "2012-09",
      "has_results": true,
      "last_update_posted_date": "2013-03-08",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01215734"
    },
    {
      "nct_id": "NCT03698279",
      "title": "Safety and Immunogenicity of Different Dosages of High-Dose Quadrivalent Influenza Vaccine in Children 6 Months to 17 Years of Age",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "High-Dose Quadrivalent Influenza Vaccine (QIV-HD) 30 μg (split-virion, inactivated)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "High-Dose Quadrivalent Influenza Vaccine (QIV-HD) 45 μg, (split-virion, inactivated)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "High-Dose Quadrivalent Influenza Vaccine (QIV-HD) 60 µg (split-virion, inactivated)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluarix Quadrivalent Influenza vaccine (Unadjuvanted QIV-SD) (Inactivated)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "FLUAD Pediatric (adjuvanted TIV) (Surface Antigen, Inactivated)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Sanofi Pasteur, a Sanofi Company",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "6 Months",
        "maximum_age": "17 Years",
        "sex": "ALL",
        "summary": "6 Months to 17 Years"
      },
      "enrollment_count": 665,
      "start_date": "2018-10-09",
      "completion_date": "2019-10-16",
      "has_results": true,
      "last_update_posted_date": "2022-04-04",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 13,
      "location_summary": "San Diego, California • Miami, Florida • Atlanta, Georgia + 8 more",
      "locations": [
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Miami",
          "state": "Florida"
        },
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "El Dorado",
          "state": "Kansas"
        },
        {
          "city": "Newton",
          "state": "Kansas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03698279"
    },
    {
      "nct_id": "NCT03068949",
      "title": "Comparison of Three Licensed Influenza Vaccines",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "FluBlok",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone",
          "type": "BIOLOGICAL"
        },
        {
          "name": "FluCelVax",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone HD",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "University of Rochester",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "49 Years",
        "sex": "ALL",
        "summary": "18 Years to 49 Years"
      },
      "enrollment_count": 413,
      "start_date": "2015-10-28",
      "completion_date": "2021-06-30",
      "has_results": true,
      "last_update_posted_date": "2021-11-30",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 1,
      "location_summary": "Rochester, New York",
      "locations": [
        {
          "city": "Rochester",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03068949"
    },
    {
      "nct_id": "NCT05650554",
      "title": "Safety and Immunogenicity of Quadrivalent Influenza mRNA Vaccine MRT5413 in Adult Participants18 Years of Age and Older",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Influenza Immunization"
      ],
      "interventions": [
        {
          "name": "Quadrivalent Influenza mRNA Vaccine MRT5413",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Recombinant Influenza Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Influenza Standard Dose Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Influenza High-Dose Vaccine",
          "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": 682,
      "start_date": "2022-12-12",
      "completion_date": "2024-04-02",
      "has_results": false,
      "last_update_posted_date": "2025-03-19",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 28,
      "location_summary": "Chula Vista, California • Gardena, California • Long Beach, California + 24 more",
      "locations": [
        {
          "city": "Chula Vista",
          "state": "California"
        },
        {
          "city": "Gardena",
          "state": "California"
        },
        {
          "city": "Long Beach",
          "state": "California"
        },
        {
          "city": "North Hollywood",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05650554"
    },
    {
      "nct_id": "NCT05163847",
      "title": "Safety and Immunogenicity of Cam2020 M2SR H3N2 Monovalent Influenza Vaccine Alone or With Licensed IIV in Older Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Influenza Vaccine"
      ],
      "interventions": [
        {
          "name": "Cam2020 M2SR H3N2 influenza vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone HD IIV",
          "type": "BIOLOGICAL"
        },
        {
          "name": "IN Placebo",
          "type": "OTHER"
        },
        {
          "name": "IM Placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "OTHER"
      ],
      "sponsor": "FluGen Inc",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": "85 Years",
        "sex": "ALL",
        "summary": "65 Years to 85 Years"
      },
      "enrollment_count": 303,
      "start_date": "2022-06-14",
      "completion_date": "2022-11-03",
      "has_results": false,
      "last_update_posted_date": "2022-11-14",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 6,
      "location_summary": "Port Orange, Florida • Meridian, Idaho • Lenexa, Kansas + 3 more",
      "locations": [
        {
          "city": "Port Orange",
          "state": "Florida"
        },
        {
          "city": "Meridian",
          "state": "Idaho"
        },
        {
          "city": "Lenexa",
          "state": "Kansas"
        },
        {
          "city": "Rochester",
          "state": "New York"
        },
        {
          "city": "Beechwood",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05163847"
    },
    {
      "nct_id": "NCT05663463",
      "title": "Seasonal Influenza Vaccine High Dose Boosting in Solid Organ Transplant Recipients",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Solid Organ Transplant"
      ],
      "interventions": [
        {
          "name": "Fluzone High-Dose - 2 doses",
          "type": "DRUG"
        },
        {
          "name": "Fluzone High-Dose - 1 dose of HD",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Minnesota",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 74,
      "start_date": "2023-09-11",
      "completion_date": "2025-06-16",
      "has_results": false,
      "last_update_posted_date": "2025-07-15",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 1,
      "location_summary": "Minneapolis, Minnesota",
      "locations": [
        {
          "city": "Minneapolis",
          "state": "Minnesota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05663463"
    },
    {
      "nct_id": "NCT03694808",
      "title": "FLUAD vs. FLUZONE HD Influenza Vaccine in Residents of Long Term Care",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Flu"
      ],
      "interventions": [
        {
          "name": "Fluad Vaccine",
          "type": "DRUG"
        },
        {
          "name": "Fluzone HD Vaccine",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "David H. Canaday",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "65 Years and older"
      },
      "enrollment_count": 478,
      "start_date": "2018-09-23",
      "completion_date": "2023-01-31",
      "has_results": true,
      "last_update_posted_date": "2024-04-30",
      "last_synced_at": "2026-09-26T06:37:00.682Z",
      "location_count": 2,
      "location_summary": "Cleveland, Ohio",
      "locations": [
        {
          "city": "Cleveland",
          "state": "Ohio"
        },
        {
          "city": "Cleveland",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03694808"
    }
  ]
}