{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=FLU+HD+vaccine&page=3",
    "query": {
      "intervention": "FLU HD vaccine",
      "page": 3
    },
    "page_size": 10
  },
  "pagination": {
    "page": 3,
    "page_size": 10,
    "total_count": 49,
    "total_pages": 5,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=FLU+HD+vaccine&page=4&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=FLU+HD+vaccine&page=2&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-04T15:16:04.356Z",
  "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": "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": "2026-10-04T15:16:04.356Z",
      "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": "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": "2026-10-04T15:16:04.356Z",
      "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": "NCT06134804",
      "title": "A Study of 9-valent Extraintestinal Pathogenic Escherichia Coli Vaccine (ExPEC9V) and High-dose Quadrivalent Influenza Vaccine, With and Without Co-administration, in Adults Aged 65 Years or Older",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Invasive Extraintestinal Pathogenic Escherichia Coli Disease (IED) Prevention"
      ],
      "interventions": [
        {
          "name": "ExPEC9V",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Placebo",
          "type": "BIOLOGICAL"
        },
        {
          "name": "HD quadrivalent influenza vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Janssen Research & Development, LLC",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "65 Years and older"
      },
      "enrollment_count": 959,
      "start_date": "2023-10-24",
      "completion_date": "2024-07-26",
      "has_results": true,
      "last_update_posted_date": "2026-04-03",
      "last_synced_at": "2026-10-04T15:16:04.356Z",
      "location_count": 24,
      "location_summary": "Huntsville, Alabama • Mobile, Alabama • San Diego, California + 19 more",
      "locations": [
        {
          "city": "Huntsville",
          "state": "Alabama"
        },
        {
          "city": "Mobile",
          "state": "Alabama"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Walnut Creek",
          "state": "California"
        },
        {
          "city": "Melbourne",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06134804"
    },
    {
      "nct_id": "NCT04077424",
      "title": "Senescent Immunity in Elders and Vaccine Responses (SILVER)",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Flu Vaccine"
      ],
      "interventions": [
        {
          "name": "Fluzone-High Dose Quadrivalent",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluad",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Flublock",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Vanderbilt University Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": "125 Years",
        "sex": "ALL",
        "summary": "65 Years to 125 Years"
      },
      "enrollment_count": 10,
      "start_date": "2019-10-21",
      "completion_date": "2020-02-01",
      "has_results": true,
      "last_update_posted_date": "2022-07-12",
      "last_synced_at": "2026-10-04T15:16:04.356Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04077424"
    },
    {
      "nct_id": "NCT05091307",
      "title": "A Study of Ad26.COV2.S and Influenza Vaccines in Healthy Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "COVID-19 Prevention"
      ],
      "interventions": [
        {
          "name": "Ad26.COV2.S",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Placebo",
          "type": "OTHER"
        },
        {
          "name": "Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "OTHER"
      ],
      "sponsor": "Janssen Vaccines & Prevention B.V.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 861,
      "start_date": "2021-11-02",
      "completion_date": "2022-11-15",
      "has_results": true,
      "last_update_posted_date": "2025-05-25",
      "last_synced_at": "2026-10-04T15:16:04.356Z",
      "location_count": 17,
      "location_summary": "Tempe, Arizona • San Diego, California • Coral Gables, Florida + 12 more",
      "locations": [
        {
          "city": "Tempe",
          "state": "Arizona"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Coral Gables",
          "state": "Florida"
        },
        {
          "city": "Fort Myers",
          "state": "Florida"
        },
        {
          "city": "Miami",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05091307"
    },
    {
      "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": "2027-12-31",
      "has_results": false,
      "last_update_posted_date": "2026-10-02",
      "last_synced_at": "2026-10-04T15:16:04.356Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04613206"
    },
    {
      "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": "2026-10-04T15:16:04.356Z",
      "location_count": 1,
      "location_summary": "Rochester, New York",
      "locations": [
        {
          "city": "Rochester",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03068949"
    },
    {
      "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": "2026-10-04T15:16:04.356Z",
      "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": "NCT03183908",
      "title": "FLUAD® vs. Fluzone® High-Dose Study",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Pain",
        "Quality of Life",
        "Injection Site Reaction",
        "Side Effect of Drug",
        "Adverse Drug Event"
      ],
      "interventions": [
        {
          "name": "FLUAD®",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone® High-Dose",
          "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": 757,
      "start_date": "2017-08-28",
      "completion_date": "2019-02-14",
      "has_results": true,
      "last_update_posted_date": "2021-03-30",
      "last_synced_at": "2026-10-04T15:16:04.356Z",
      "location_count": 4,
      "location_summary": "Atlanta, Georgia • Boston, Massachusetts • Durham, North Carolina + 1 more",
      "locations": [
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "Boston",
          "state": "Massachusetts"
        },
        {
          "city": "Durham",
          "state": "North Carolina"
        },
        {
          "city": "Cincinnati",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03183908"
    },
    {
      "nct_id": "NCT04484532",
      "title": "Evaluation of Antibody Response to High-Dose Seasonal Influenza Vaccination in Patients With Myeloid Malignancy Receiving Chemotherapy and Healthy Volunteers",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "EARLY_PHASE1"
      ],
      "conditions": [
        "Acute Myeloid Leukemia",
        "Myelodysplastic Syndrome"
      ],
      "interventions": [
        {
          "name": "Trivalent Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Roswell Park Cancer Institute",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "40 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "40 Years and older"
      },
      "enrollment_count": 130,
      "start_date": "2017-10-17",
      "completion_date": "2022-06-07",
      "has_results": false,
      "last_update_posted_date": "2023-06-06",
      "last_synced_at": "2026-10-04T15:16:04.356Z",
      "location_count": 1,
      "location_summary": "Buffalo, New York",
      "locations": [
        {
          "city": "Buffalo",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04484532"
    }
  ]
}