{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Quadrivalent+Influenza+High-Dose+Vaccine",
    "query": {
      "intervention": "Quadrivalent Influenza High-Dose 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=Quadrivalent+Influenza+High-Dose+Vaccine&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-10-05T21:44:33.109Z",
  "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": "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": "2026-10-05T21:44:33.109Z",
      "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": "NCT02831751",
      "title": "Immunogenicity, Safety, and Tolerability of a Plant-Derived Quadrivalent VLP Influenza Vaccine in Elderly Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Virus Diseases",
        "RNA Virus Infections",
        "Respiratory Tract Diseases",
        "Respiratory Tract Infections"
      ],
      "interventions": [
        {
          "name": "30 µg/strain of Quadrivalent VLP Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "60 µg/strain of Quadrivalent VLP Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "FluLaval® Tetra (15 µg/strain)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone® High-Dose (60 µg/strain)",
          "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": 1001,
      "start_date": "2016-04",
      "completion_date": "2017-01",
      "has_results": false,
      "last_update_posted_date": "2019-10-25",
      "last_synced_at": "2026-10-05T21:44:33.109Z",
      "location_count": 6,
      "location_summary": "Redding, California • Hollywood, Florida • South Miami, Florida + 3 more",
      "locations": [
        {
          "city": "Redding",
          "state": "California"
        },
        {
          "city": "Hollywood",
          "state": "Florida"
        },
        {
          "city": "South Miami",
          "state": "Florida"
        },
        {
          "city": "Savannah",
          "state": "Georgia"
        },
        {
          "city": "Omaha",
          "state": "Nebraska"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02831751"
    },
    {
      "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": "2026-10-05T21:44:33.109Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04077424"
    },
    {
      "nct_id": "NCT05518500",
      "title": "A Deep Longitudinal Analysis of Next Generation Influenza Vaccines in Older Adults",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Aging",
        "Influenza Vaccine",
        "Dendritic Cell",
        "Vaccine Response"
      ],
      "interventions": [
        {
          "name": "Flu Vaccine (Year 1)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Flu Vaccine (Year 2)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Flu Vaccine (Year 3)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Flu Vaccine (Year 4)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "The Jackson Laboratory",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "65 Years and older"
      },
      "enrollment_count": 75,
      "start_date": "2022-08-31",
      "completion_date": "2026-12-31",
      "has_results": false,
      "last_update_posted_date": "2026-08-03",
      "last_synced_at": "2026-10-05T21:44:33.109Z",
      "location_count": 1,
      "location_summary": "Farmington, Connecticut",
      "locations": [
        {
          "city": "Farmington",
          "state": "Connecticut"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05518500"
    },
    {
      "nct_id": "NCT03617523",
      "title": "Safety and Immunogenicity of Fluzone® Quadrivalent, Flublok® Quadrivalent, and Fluzone® High-Dose, Influenza Vaccines, 2018-2019 Formulations",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Fluzone Quadrivalent vaccine, 2018-2019 formulation",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Flublok Quadrivalent vaccine, 2018-2019 formulation",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone High-Dose vaccine, 2018-2019 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": null,
        "sex": "ALL",
        "summary": "6 Months and older"
      },
      "enrollment_count": 240,
      "start_date": "2018-09-10",
      "completion_date": "2018-11-12",
      "has_results": true,
      "last_update_posted_date": "2022-03-29",
      "last_synced_at": "2026-10-05T21:44:33.109Z",
      "location_count": 3,
      "location_summary": "Bardstown, Kentucky • Metairie, Louisiana • Salt Lake City, Utah",
      "locations": [
        {
          "city": "Bardstown",
          "state": "Kentucky"
        },
        {
          "city": "Metairie",
          "state": "Louisiana"
        },
        {
          "city": "Salt Lake City",
          "state": "Utah"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03617523"
    },
    {
      "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": "2026-10-05T21:44:33.109Z",
      "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": "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": "2026-10-05T21:44:33.109Z",
      "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": "NCT05755620",
      "title": "A Study to Evaluate the Safety and Immunogenicity of a Single Dose of H1ssF-3928 mRNA-LNP in Healthy Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Influenza Virus Quadrivalent Inactivated Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Sodium Chloride, 0.9%",
          "type": "OTHER"
        },
        {
          "name": "VRC-FLUNPF099-00-VP (H1ssF_3928)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "OTHER"
      ],
      "sponsor": "National Institute of Allergy and Infectious Diseases (NIAID)",
      "sponsor_class": "NIH",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "49 Years",
        "sex": "ALL",
        "summary": "18 Years to 49 Years"
      },
      "enrollment_count": 50,
      "start_date": "2023-04-05",
      "completion_date": "2025-10-03",
      "has_results": false,
      "last_update_posted_date": "2026-06-18",
      "last_synced_at": "2026-10-05T21:44:33.109Z",
      "location_count": 1,
      "location_summary": "Durham, North Carolina",
      "locations": [
        {
          "city": "Durham",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05755620"
    },
    {
      "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": "2026-10-05T21:44:33.109Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04613206"
    },
    {
      "nct_id": "NCT05945485",
      "title": "A Study to Evaluate the Safety and Immunogenicity of Two Doses of DCVC H1 HA mRNA-LNP in Healthy Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "DCVC H1 HA mRNA vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Recombinant Seasonal Influenza Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Sodium Chloride, 0.9%",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "OTHER"
      ],
      "sponsor": "National Institute of Allergy and Infectious Diseases (NIAID)",
      "sponsor_class": "NIH",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "49 Years",
        "sex": "ALL",
        "summary": "18 Years to 49 Years"
      },
      "enrollment_count": 50,
      "start_date": "2023-10-16",
      "completion_date": "2026-05-21",
      "has_results": false,
      "last_update_posted_date": "2026-06-22",
      "last_synced_at": "2026-10-05T21:44:33.109Z",
      "location_count": 1,
      "location_summary": "Iowa City, Iowa",
      "locations": [
        {
          "city": "Iowa City",
          "state": "Iowa"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05945485"
    }
  ]
}