{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Challenge+Strain",
    "query": {
      "intervention": "Challenge Strain"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 66,
    "total_pages": 7,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Challenge+Strain&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-09T12:40:31.322Z",
  "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": "NCT03840811",
      "title": "Experimental Human Infection With Neisseria Gonorrhoeae",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Gonococcal Infection"
      ],
      "interventions": [
        {
          "name": "Cefixime",
          "type": "DRUG"
        },
        {
          "name": "Ceftriaxone",
          "type": "DRUG"
        },
        {
          "name": "Ciprofloxacin",
          "type": "DRUG"
        },
        {
          "name": "Neisseria gonorrhoeae strain FA1090 A26",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Neisseria gonorrhoeae strain FA7537",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "DRUG",
        "BIOLOGICAL"
      ],
      "sponsor": "National Institute of Allergy and Infectious Diseases (NIAID)",
      "sponsor_class": "NIH",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "36 Years",
        "sex": "MALE",
        "summary": "18 Years to 36 Years · Male only"
      },
      "enrollment_count": 27,
      "start_date": "2017-04-23",
      "completion_date": "2019-11-25",
      "has_results": true,
      "last_update_posted_date": "2021-03-23",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 1,
      "location_summary": "Chapel Hill, North Carolina",
      "locations": [
        {
          "city": "Chapel Hill",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03840811"
    },
    {
      "nct_id": "NCT03527173",
      "title": "A Study to Evaluate the Efficacy, Safety and Immunogenicity of a Vaccine Designed to Protect Against Infection With Shigella Sonnei in Healthy Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Dysentery, Bacillary"
      ],
      "interventions": [
        {
          "name": "S.sonnei vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        },
        {
          "name": "S. sonnei 53G challenge strain",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "DRUG"
      ],
      "sponsor": "GlaxoSmithKline",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 71,
      "start_date": "2018-08-29",
      "completion_date": "2019-11-11",
      "has_results": true,
      "last_update_posted_date": "2020-07-28",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 1,
      "location_summary": "Cincinnati, Ohio",
      "locations": [
        {
          "city": "Cincinnati",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03527173"
    },
    {
      "nct_id": "NCT04978454",
      "title": "Influenza Challenge Study to Determine the Optimal Infection Dose and Safety of a Recombinant H3N2 (A/Texas/71/2017 (H3N2, Clade 3C3a) Influenza Strain",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Influenza"
      ],
      "interventions": [
        {
          "name": "Influenza RG-A/Texas/71/2017 (H3N2) Challenge",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Placebo",
          "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": "45 Years",
        "sex": "ALL",
        "summary": "18 Years to 45 Years"
      },
      "enrollment_count": 60,
      "start_date": "2021-08-19",
      "completion_date": "2022-09-22",
      "has_results": true,
      "last_update_posted_date": "2025-08-28",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "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/NCT04978454"
    },
    {
      "nct_id": "NCT04966871",
      "title": "Safety, Tolerability and Efficacy of PfSPZ Vaccine Against Heterologous CHMI in US Malaria naïve Adults",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Malaria"
      ],
      "interventions": [
        {
          "name": "PfSPZ Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "PfSPZ Challenge (7G8) for CHMI",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Normal Saline",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "OTHER"
      ],
      "sponsor": "Sanaria Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 54,
      "start_date": "2021-09-27",
      "completion_date": "2022-06-21",
      "has_results": false,
      "last_update_posted_date": "2022-07-18",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 1,
      "location_summary": "Seattle, Washington",
      "locations": [
        {
          "city": "Seattle",
          "state": "Washington"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04966871"
    },
    {
      "nct_id": "NCT02780154",
      "title": "PfSPZ Challenge in Non-immune Adults in Baltimore, USA",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Plasmodium Falciparum Infection"
      ],
      "interventions": [
        {
          "name": "PfSPZ (7G8) Challenge",
          "type": "BIOLOGICAL"
        },
        {
          "name": "PfSPZ (NF54) Challenge",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "National Institute of Allergy and Infectious Diseases (NIAID)",
      "sponsor_class": "NIH",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "45 Years",
        "sex": "ALL",
        "summary": "18 Years to 45 Years"
      },
      "enrollment_count": 30,
      "start_date": "2016-08-25",
      "completion_date": "2016-12-15",
      "has_results": false,
      "last_update_posted_date": "2019-01-28",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 1,
      "location_summary": "Baltimore, Maryland",
      "locations": [
        {
          "city": "Baltimore",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02780154"
    },
    {
      "nct_id": "NCT01632787",
      "title": "Utility of a Survey Instrument to Predict Benefit From a Novel Treatment for Vertical Heterophoria",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Binocular Vision Dysfunction",
        "Vertical Heterophoria"
      ],
      "interventions": [
        {
          "name": "Questionnaires and Optometrist Prism Challenge/Treatment",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "Vision Specialists of Birmingham",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 86,
      "start_date": "2012-04",
      "completion_date": "2016-04",
      "has_results": false,
      "last_update_posted_date": "2017-11-01",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 2,
      "location_summary": "Bloomfield Hills, Michigan • Livonia, Michigan",
      "locations": [
        {
          "city": "Bloomfield Hills",
          "state": "Michigan"
        },
        {
          "city": "Livonia",
          "state": "Michigan"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01632787"
    },
    {
      "nct_id": "NCT01060748",
      "title": "Safety and Efficacy Study of a Vaccine Against Enterotoxigenic Escherichia Coli (ETEC) to Prevent Moderate to Severe Diarrhea",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Diarrhea"
      ],
      "interventions": [
        {
          "name": "ACE527",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Placebo",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "TD Vaccines A/S",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 70,
      "start_date": "2010-03",
      "completion_date": "2010-10",
      "has_results": false,
      "last_update_posted_date": "2011-03-07",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 1,
      "location_summary": "Baltimore, Maryland",
      "locations": [
        {
          "city": "Baltimore",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01060748"
    },
    {
      "nct_id": "NCT00844493",
      "title": "Low-dose Challenge Model With Enterotoxigenic E Coli",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Diarrhea"
      ],
      "interventions": [
        {
          "name": "E coli strain H10407 and buffer",
          "type": "BIOLOGICAL"
        },
        {
          "name": "E coli H10407 and buffer",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Johns Hopkins Bloomberg School of Public Health",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "45 Years",
        "sex": "ALL",
        "summary": "18 Years to 45 Years"
      },
      "enrollment_count": 30,
      "start_date": "2009-02",
      "completion_date": "2013-06",
      "has_results": false,
      "last_update_posted_date": "2014-09-12",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 1,
      "location_summary": "Baltimore, Maryland",
      "locations": [
        {
          "city": "Baltimore",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00844493"
    },
    {
      "nct_id": "NCT07558122",
      "title": "Malaria CVD 36000; Gates INV090205",
      "overall_status": "NOT_YET_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Malaria (Plasmodium Falciparum)"
      ],
      "interventions": [
        {
          "name": "PfSPZ Challenge (NF54)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Wearable Biosensor Devices",
          "type": "DEVICE"
        },
        {
          "name": "Placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "DEVICE",
        "OTHER"
      ],
      "sponsor": "University of Maryland, Baltimore",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 32,
      "start_date": "2026-11",
      "completion_date": "2026-12",
      "has_results": false,
      "last_update_posted_date": "2026-09-09",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 1,
      "location_summary": "Baltimore, Maryland",
      "locations": [
        {
          "city": "Baltimore",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT07558122"
    },
    {
      "nct_id": "NCT01058226",
      "title": "Reproducibility of Malaria Challenge in Healthy Volunteers",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Healthy"
      ],
      "interventions": [
        {
          "name": "Malaria challenge (wild-type NF54 strain Plasmodium falciparum sporozoites)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Seattle Children's Hospital",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 6,
      "start_date": "2010-02",
      "completion_date": "2010-09",
      "has_results": false,
      "last_update_posted_date": "2011-03-31",
      "last_synced_at": "2026-09-09T12:40:31.322Z",
      "location_count": 1,
      "location_summary": "Seattle, Washington",
      "locations": [
        {
          "city": "Seattle",
          "state": "Washington"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01058226"
    }
  ]
}