{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Quadrivalent+inactivated+influenza+vaccine+%28IIV%29",
    "query": {
      "intervention": "Quadrivalent inactivated influenza vaccine (IIV)"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 19,
    "total_pages": 2,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Quadrivalent+inactivated+influenza+vaccine+%28IIV%29&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-10-09T06:27:34.278Z",
  "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": "NCT01997450",
      "title": "A Case Control Study of the Effectiveness of Q/LAIV Versus Inactivated Influenza Vaccine and No Vaccine in Subjects 2-17 Years of Age",
      "overall_status": "TERMINATED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Influenza Vaccine Effectiveness"
      ],
      "interventions": [],
      "intervention_types": [],
      "sponsor": "MedImmune LLC",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "2 Years",
        "maximum_age": "17 Years",
        "sex": "ALL",
        "summary": "2 Years to 17 Years"
      },
      "enrollment_count": 4121,
      "start_date": "2013-12-02",
      "completion_date": "2016-04-15",
      "has_results": false,
      "last_update_posted_date": "2025-03-10",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 8,
      "location_summary": "Gainesville, Florida • Bloomington, Minnesota • Winston-Salem, North Carolina + 5 more",
      "locations": [
        {
          "city": "Gainesville",
          "state": "Florida"
        },
        {
          "city": "Bloomington",
          "state": "Minnesota"
        },
        {
          "city": "Winston-Salem",
          "state": "North Carolina"
        },
        {
          "city": "Akron",
          "state": "Ohio"
        },
        {
          "city": "Portland",
          "state": "Oregon"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01997450"
    },
    {
      "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": "2026-10-09T06:27:34.278Z",
      "location_count": 1,
      "location_summary": "St Louis, Missouri",
      "locations": [
        {
          "city": "St Louis",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02500680"
    },
    {
      "nct_id": "NCT03898973",
      "title": "Response to Inactivated Influenza Vaccine in Lymph Tissue and Blood",
      "overall_status": "WITHDRAWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Quadrivalent inactivated influenza vaccine (IIV)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Stanford University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "20 Years",
        "maximum_age": "75 Years",
        "sex": "ALL",
        "summary": "20 Years to 75 Years"
      },
      "enrollment_count": 0,
      "start_date": "2019-04-11",
      "completion_date": "2023-11-17",
      "has_results": false,
      "last_update_posted_date": "2023-11-21",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 1,
      "location_summary": "Stanford, California",
      "locations": [
        {
          "city": "Stanford",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03898973"
    },
    {
      "nct_id": "NCT06503900",
      "title": "Simultaneous mRNA COVID-19 and IIV Vaccination in Pregnancy Study",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Birth Outcomes",
        "Safety",
        "Adverse Event Following Immunization"
      ],
      "interventions": [
        {
          "name": "mRNA COVID-19 vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "IIV4 (quadrivalent inactivated influenza vaccine)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Duke University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 98,
      "start_date": "2024-09-12",
      "completion_date": "2025-11-19",
      "has_results": true,
      "last_update_posted_date": "2026-10-07",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 6,
      "location_summary": "Atlanta, Georgia • Boston, Massachusetts • Durham, North Carolina + 2 more",
      "locations": [
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "Boston",
          "state": "Massachusetts"
        },
        {
          "city": "Durham",
          "state": "North Carolina"
        },
        {
          "city": "Winston-Salem",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06503900"
    },
    {
      "nct_id": "NCT03845231",
      "title": "Mucosal and Systemic Immunity After Viral Challenge of Healthy Volunteers Vaccinated With Inactivated Influenza Vaccine Via the Intranasal Versus Intramuscular Route",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Flucelvax(R)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Human Challenge virus",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "OTHER"
      ],
      "sponsor": "National Institute of Allergy and Infectious Diseases (NIAID)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "55 Years",
        "sex": "ALL",
        "summary": "18 Years to 55 Years"
      },
      "enrollment_count": 82,
      "start_date": "2019-04-29",
      "completion_date": "2020-10-28",
      "has_results": false,
      "last_update_posted_date": "2020-11-10",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 1,
      "location_summary": "Bethesda, Maryland",
      "locations": [
        {
          "city": "Bethesda",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03845231"
    },
    {
      "nct_id": "NCT02967393",
      "title": "Influenza Vaccine Feasibility Study in Children With Persistent Asthma",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Asthmatic"
      ],
      "interventions": [
        {
          "name": "ccIIV4",
          "type": "DRUG"
        },
        {
          "name": "IIV4",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Vanderbilt University Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "5 Years",
        "maximum_age": "11 Years",
        "sex": "ALL",
        "summary": "5 Years to 11 Years"
      },
      "enrollment_count": 40,
      "start_date": "2016-10-10",
      "completion_date": "2017-02-01",
      "has_results": true,
      "last_update_posted_date": "2018-04-23",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 4,
      "location_summary": "Atlanta, Georgia • Durham, North Carolina • Cincinnati, Ohio + 1 more",
      "locations": [
        {
          "city": "Atlanta",
          "state": "Georgia"
        },
        {
          "city": "Durham",
          "state": "North Carolina"
        },
        {
          "city": "Cincinnati",
          "state": "Ohio"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02967393"
    },
    {
      "nct_id": "NCT06029933",
      "title": "Fluad vs. Fluzone High-Dose Vaccine Effectiveness Among Adults ≥65 Years",
      "overall_status": "RECRUITING",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Influenza",
        "Community-acquired Pneumonia",
        "Cardiovascular Events"
      ],
      "interventions": [
        {
          "name": "Adjuvanted Quadrivalent Inactivated Influenza Vaccine (aIIV4)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "High-Dose Quadrivalent Inactivated Influenza Vaccine (HD-IIV4)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Kaiser Permanente",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "65 Years and older"
      },
      "enrollment_count": 1500000,
      "start_date": "2023-08-17",
      "completion_date": "2028-05",
      "has_results": false,
      "last_update_posted_date": "2026-08-05",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 1,
      "location_summary": "Oakland, California",
      "locations": [
        {
          "city": "Oakland",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06029933"
    },
    {
      "nct_id": "NCT03969641",
      "title": "Safety of RIV4 Versus IIV4 in Pregnant Women",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Safety",
        "Adverse Event Following Immunisation",
        "Birth Outcomes"
      ],
      "interventions": [
        {
          "name": "Quadrivalent Recombinant Influenza Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quadrivalent Inactivated Influenza Vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Duke University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 384,
      "start_date": "2019-09-05",
      "completion_date": "2021-09-29",
      "has_results": true,
      "last_update_posted_date": "2023-01-11",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 3,
      "location_summary": "Boston, Massachusetts • Durham, North Carolina • Cincinnati, Ohio",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        },
        {
          "city": "Durham",
          "state": "North Carolina"
        },
        {
          "city": "Cincinnati",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03969641"
    },
    {
      "nct_id": "NCT05501561",
      "title": "Safety and Immunogenicity of Different Formulations of an MF59-Adjuvanted Influenza Vaccine in Older Adults ≥50 Years of Age",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Influenza, Human"
      ],
      "interventions": [
        {
          "name": "Experimental: IIV-A Investigational IIV-A administered as a single dose intramuscularly on Day 1",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Experimental: aIIV-B Investigational aIIV-B administered as a single dose intramuscularly on Day 1",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Experimental: aIIV-C Investigational aIIV-C administered as a single dose intramuscularly on Day 1",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Active Comparator: Licensed IIV IIV administered as a single dose intramuscularly on Day 1",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Seqirus",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "50 Years and older"
      },
      "enrollment_count": 1056,
      "start_date": "2022-08-25",
      "completion_date": "2023-03-31",
      "has_results": true,
      "last_update_posted_date": "2026-06-30",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 47,
      "location_summary": "Tempe, Arizona • Huntington Beach, California • San Diego, California + 42 more",
      "locations": [
        {
          "city": "Tempe",
          "state": "Arizona"
        },
        {
          "city": "Huntington Beach",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Colorado Springs",
          "state": "Colorado"
        },
        {
          "city": "Milford",
          "state": "Connecticut"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05501561"
    },
    {
      "nct_id": "NCT03888989",
      "title": "Response to Influenza Vaccine During Pregnancy",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Quadrivalent inactivated influenza vaccine (IIV)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Stanford University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "49 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 49 Years · Female only"
      },
      "enrollment_count": 2,
      "start_date": "2019-09-30",
      "completion_date": "2023-12-31",
      "has_results": true,
      "last_update_posted_date": "2025-02-17",
      "last_synced_at": "2026-10-09T06:27:34.278Z",
      "location_count": 1,
      "location_summary": "Stanford, California",
      "locations": [
        {
          "city": "Stanford",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03888989"
    }
  ]
}