{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Quadrivalent+High-dose+Influenza+Vaccine",
    "query": {
      "intervention": "Quadrivalent High-dose 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=Quadrivalent+High-dose+Influenza+Vaccine&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-10-02T14:03:00.765Z",
  "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": "2026-10-02T14:03:00.765Z",
      "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": "NCT05947071",
      "title": "High vs.Standard Dose Influenza Vaccine in Pediatric Solid Organ Transplant (SOT) Recipients",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Immunization; Infection",
        "Transplantation Infection",
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Standard Dose Quadrivalent Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "High Dose Quadrivalent Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "National Institute of Allergy and Infectious Diseases (NIAID)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "3 Years",
        "maximum_age": "17 Years",
        "sex": "ALL",
        "summary": "3 Years to 17 Years"
      },
      "enrollment_count": 312,
      "start_date": "2024-09-26",
      "completion_date": "2027-09-01",
      "has_results": false,
      "last_update_posted_date": "2026-09-24",
      "last_synced_at": "2026-10-02T14:03:00.765Z",
      "location_count": 10,
      "location_summary": "Stanford, California • Atlanta, Georgia • Chicago, Illinois + 7 more",
      "locations": [
        {
          "city": "Stanford",
          "state": "California"
        },
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Kansas City",
          "state": "Missouri"
        },
        {
          "city": "Cincinnati",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05947071"
    },
    {
      "nct_id": "NCT04487041",
      "title": "Tfh Dysfunction in HIV and Aging",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Human Influenza"
      ],
      "interventions": [
        {
          "name": "Standard dose influenza vaccination",
          "type": "BIOLOGICAL"
        },
        {
          "name": "High dose influenza vaccination",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "University of Miami",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 400,
      "start_date": "2020-10-30",
      "completion_date": "2027-12-30",
      "has_results": false,
      "last_update_posted_date": "2026-07-17",
      "last_synced_at": "2026-10-02T14:03:00.765Z",
      "location_count": 1,
      "location_summary": "Miami, Florida",
      "locations": [
        {
          "city": "Miami",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04487041"
    },
    {
      "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": "2026-10-02T14:03:00.765Z",
      "location_count": 1,
      "location_summary": "Farmington, Connecticut",
      "locations": [
        {
          "city": "Farmington",
          "state": "Connecticut"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05518500"
    },
    {
      "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": "2026-10-02T14:03:00.765Z",
      "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"
    },
    {
      "nct_id": "NCT02233816",
      "title": "Immunogenicity, Safety and Tolerability of a Plant-Derived Seasonal Virus-Like-Particle Quadrivalent Influenza Vaccine in Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Virus Diseases",
        "RNA Virus Infections",
        "Respiratory Tract Diseases",
        "Respiratory Tract Infections"
      ],
      "interventions": [
        {
          "name": "Low dose of quadrivalent VLP vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Medium dose of quadrivalent VLP vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "High dose of quadrivalent VLP vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Placebo",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Medicago",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "49 Years",
        "sex": "ALL",
        "summary": "18 Years to 49 Years"
      },
      "enrollment_count": 300,
      "start_date": "2014-07-28",
      "completion_date": "2015-06-22",
      "has_results": false,
      "last_update_posted_date": "2019-11-13",
      "last_synced_at": "2026-10-02T14:03:00.765Z",
      "location_count": 2,
      "location_summary": "Hollywood, Florida • Miami, Florida",
      "locations": [
        {
          "city": "Hollywood",
          "state": "Florida"
        },
        {
          "city": "Miami",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02233816"
    },
    {
      "nct_id": "NCT05624606",
      "title": "Safety and Immunogenicity of Quadrivalent Influenza mRNA Vaccine MRT5410 in Adult Participants 18 Years of Age and Older",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Influenza Immunization"
      ],
      "interventions": [
        {
          "name": "Quadrivalent Influenza mRNA Vaccine MRT5410",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Recombinant Influenza vaccine RIV4",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Inactivated Influenza Standard Dose QIV-SD",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Inactivated Influenza High Dose QIV-HD",
          "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": "2022-11-28",
      "completion_date": "2024-03-28",
      "has_results": false,
      "last_update_posted_date": "2025-03-18",
      "last_synced_at": "2026-10-02T14:03:00.765Z",
      "location_count": 23,
      "location_summary": "Huntington Park, California • Long Beach, California • North Hollywood, California + 19 more",
      "locations": [
        {
          "city": "Huntington Park",
          "state": "California"
        },
        {
          "city": "Long Beach",
          "state": "California"
        },
        {
          "city": "North Hollywood",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Gainesville",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05624606"
    },
    {
      "nct_id": "NCT06361875",
      "title": "A Study to Investigate the Safety and Immunogenicity of the Quadrivalent Influenza mRNA Vaccines in Adults Aged 18 Years and Above",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Influenza Immunization",
        "Healthy Volunteers"
      ],
      "interventions": [
        {
          "name": "Quadrivalent Influenza mRNA Vaccine MRT5421",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Influenza mRNA Vaccine MRT5424",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Influenza mRNA Vaccine MRT5429",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Influenza Standard Dose Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Influenza High-Dose Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Recombinant Influenza 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": 908,
      "start_date": "2024-04-01",
      "completion_date": "2025-06-09",
      "has_results": true,
      "last_update_posted_date": "2026-08-04",
      "last_synced_at": "2026-10-02T14:03:00.765Z",
      "location_count": 11,
      "location_summary": "San Diego, California • Hialeah, Florida • Hollywood, Florida + 8 more",
      "locations": [
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Hialeah",
          "state": "Florida"
        },
        {
          "city": "Hollywood",
          "state": "Florida"
        },
        {
          "city": "Indianapolis",
          "state": "Indiana"
        },
        {
          "city": "Lexington",
          "state": "Kentucky"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06361875"
    },
    {
      "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": "2026-10-02T14:03:00.765Z",
      "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": "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": "2026-10-02T14:03:00.765Z",
      "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"
    }
  ]
}