{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=HD+quadrivalent+influenza+vaccine&page=2",
    "query": {
      "intervention": "HD quadrivalent influenza vaccine",
      "page": 2
    },
    "page_size": 10
  },
  "pagination": {
    "page": 2,
    "page_size": 10,
    "total_count": 30,
    "total_pages": 3,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=HD+quadrivalent+influenza+vaccine&page=3&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=HD+quadrivalent+influenza+vaccine&page=1&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-07T08:08:17.045Z",
  "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": "NCT02500680",
      "title": "The Safety, Tolerance, and Immunogenicity of MAS-1-Adjuvanted Seasonal Inactivated Influenza Vaccine (MER4101)",
      "overall_status": "UNKNOWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Influenza, Human"
      ],
      "interventions": [
        {
          "name": "MER4101",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Nova Immunotherapeutics Limited",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 102,
      "start_date": "2015-07",
      "completion_date": "2020-12",
      "has_results": false,
      "last_update_posted_date": "2019-09-06",
      "last_synced_at": "2026-10-07T08:08:17.045Z",
      "location_count": 1,
      "location_summary": "St Louis, Missouri",
      "locations": [
        {
          "city": "St Louis",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02500680"
    },
    {
      "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": "2026-10-07T08:08:17.045Z",
      "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": "NCT05827978",
      "title": "Study of mRNA-1010 Seasonal Influenza Vaccine in Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Seasonal Influenza"
      ],
      "interventions": [
        {
          "name": "mRNA-1010",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Licensed Quadrivalent Inactivated Seasonal Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "ModernaTX, Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 8411,
      "start_date": "2023-04-17",
      "completion_date": "2024-06-24",
      "has_results": true,
      "last_update_posted_date": "2025-07-10",
      "last_synced_at": "2026-10-07T08:08:17.045Z",
      "location_count": 103,
      "location_summary": "Anniston, Alabama • Athens, Alabama • Cullman, Alabama + 85 more",
      "locations": [
        {
          "city": "Anniston",
          "state": "Alabama"
        },
        {
          "city": "Athens",
          "state": "Alabama"
        },
        {
          "city": "Cullman",
          "state": "Alabama"
        },
        {
          "city": "Huntsville",
          "state": "Alabama"
        },
        {
          "city": "Mesa",
          "state": "Arizona"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05827978"
    },
    {
      "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": "2026-10-07T08:08:17.045Z",
      "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": "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": "2026-10-07T08:08:17.045Z",
      "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": "NCT06060457",
      "title": "A Study to Evaluate the Safety and Immune Response of mRNA-1345, a Vaccine Targeting Respiratory Syncytial Virus (RSV), When Co-administered With a Fluzone HD, in Adults ≥65 Years of Age",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Respiratory Syncytial Virus"
      ],
      "interventions": [
        {
          "name": "Placebo",
          "type": "BIOLOGICAL"
        },
        {
          "name": "mRNA-1345",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Fluzone HD",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "ModernaTX, Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "65 Years and older"
      },
      "enrollment_count": 1900,
      "start_date": "2023-09-25",
      "completion_date": "2024-06-07",
      "has_results": true,
      "last_update_posted_date": "2025-07-30",
      "last_synced_at": "2026-10-07T08:08:17.045Z",
      "location_count": 34,
      "location_summary": "Scottsdale, Arizona • Dublin, California • Riverside, California + 29 more",
      "locations": [
        {
          "city": "Scottsdale",
          "state": "Arizona"
        },
        {
          "city": "Scottsdale",
          "state": "Arizona"
        },
        {
          "city": "Dublin",
          "state": "California"
        },
        {
          "city": "Riverside",
          "state": "California"
        },
        {
          "city": "Rolling Hills Estates",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06060457"
    },
    {
      "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": "2026-10-07T08:08:17.045Z",
      "location_count": 1,
      "location_summary": "Farmington, Connecticut",
      "locations": [
        {
          "city": "Farmington",
          "state": "Connecticut"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05518500"
    },
    {
      "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": "2026-10-07T08:08:17.045Z",
      "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": "NCT05553301",
      "title": "Safety and Immunogenicity of Quadrivalent Influenza mRNA Vaccine MRT5407 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 MRT5407",
          "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": 560,
      "start_date": "2022-10-03",
      "completion_date": "2024-01-19",
      "has_results": false,
      "last_update_posted_date": "2025-01-24",
      "last_synced_at": "2026-10-07T08:08:17.045Z",
      "location_count": 23,
      "location_summary": "Rolling Hills Estates, California • San Diego, California • DeLand, Florida + 16 more",
      "locations": [
        {
          "city": "Rolling Hills Estates",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "DeLand",
          "state": "Florida"
        },
        {
          "city": "Gainesville",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05553301"
    },
    {
      "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": "2026-10-07T08:08:17.045Z",
      "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"
    }
  ]
}