Influenza Challenge Study to Determine the Optimal Infection Dose and Safety of a Recombinant H3N2 (A/Texas/71/2017 (H3N2, Clade 3C3a) Influenza Strain
Public ClinicalTrials.gov record NCT04978454. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
A Multicenter, Blinded, Randomized, Placebo-Controlled, Dose-Ranging Influenza Challenge Study in Healthy Adult Volunteers to Determine the Optimal Infection Dose and Safety of a Recombinant H3N2 (A/Texas/71/2017 (H3N2), Clade 3C3a) Influenza Challenge Virus
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
An open-label, dose-ranging influenza challenge study in healthy adult volunteers to determine the optimal infection dose and safety of a recombinant H3N2 (A/Texas/ A/Texas/71/2017 (H3N2, clade 3C3a) influenza strain. The goal of this study is to find a challenge virus dose that is safe and can achieve a symptomatic influenza Attack Rate (AR) that will be sufficiently high for utilization in future vaccine or intervention studies. The optimal dose of the three considered is broadly defined as the minimum challenge virus dose that elicits the highest AR without meeting safety-stopping criteria. Additionally, viral recovery, clinical symptoms, and immune responses over the post-challenge period will be described by challenge dose group. This study will last for up to 1 year depending upon the number of challenge cohorts enrolled given the adaptive dose-escalation design. The populations are healthy males and non-pregnant, non-breastfeeding females aged = 18 and \< 46 years of age with a serum HAI antibody titer of \</=1:40 against influenza A/Texas/71/2017 (H3N2), clade 3C3a. The study will enroll and challenge up to 106 (plus 8 shams) healthy adult volunteers with the H3N2 (A/Texas/71/2017 (H3N2), clade 3C3a) influenza virus challenge strain. The primary objectives are: 1) To determine the optimal infectious dose of a recombinant influenza virus (A/Texas/71/2017 (H3N2), clade 3C3a) to be used as a clinical challenge strain in future vaccine efficacy or intervention studies as assessed by viral shedding and clinical symptoms. 2) To describe viral detection by quantitative and qualitative Reverse Transcription - Polymerase Chain Reaction (RT-PCR) from study subjects at baseline and post-challenge. 3) To document clinical symptoms from self-reported surveys and standardized symptom scales at baseline and post-challenge.
Study identification
- NCT ID
- NCT04978454
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 1
- Enrollment
- 60 participants
Conditions and interventions
Conditions
Interventions
- Influenza RG-A/Texas/71/2017 (H3N2) Challenge Biological
- Placebo Other
Biological · Other
Eligibility (public fields only)
- Age range
- 18 Years to 45 Years
- Sex
- All
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Aug 18, 2021
- Primary completion
- Sep 21, 2022
- Completion
- Sep 21, 2022
- Last update posted
- Aug 27, 2025
2021 – 2022
United States locations
- U.S. sites
- 2
- U.S. states
- 2
- U.S. cities
- 2
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| University of Maryland, School of Medicine, Center for Vaccine Development and Global Health | Baltimore | Maryland | 21201-4606 | — |
| Duke University Trent Drive | Durham | North Carolina | 27710 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04978454, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Aug 27, 2025 · Synced Sep 5, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04978454 live on ClinicalTrials.gov.