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A Study of Ad26.COV2.S Administered as Booster Vaccination in Adults Who Have Previously Received Primary Vaccination With Ad26.COV2.S or BNT162b2
NCT04999111 · View on ClinicalTrials.gov ↗
Study Summary
The purposes of this study are to demonstrate the non-inferiority (NI) of the neutralizing antibody response to the original strain 14 days after booster vaccination with Ad26.COV2.S at the different dose levels, administered greater than or equal to (\>=) 6 months after single-dose primary vaccination with Ad26.COV2.S, compared to the neutralizing antibody response to the original strain induced by single-dose primary vaccination with Ad26.COV2.S; To demonstrate the NI of the neutralizing antibody response to the leading variant of high consequence or concern 14 days after booster vaccination with Ad26.COV2.S at the 5\*10\^10 virus particle (vp) dose level, administered \>= 6 months after single-dose primary vaccination with Ad26.COV2.S (5\*10\^10 vp dose level), compared to the neutralizing antibody response to the leading variant of high consequence or concern induced by single-dose primary vaccination with Ad26.COV2.S at the 5\*10\^10 vp dose level, if feasible; To demonstrate the NI of the neutralizing antibody response to the original strain 14 days after booster vaccination with Ad26.COV2.S at the different dose levels administered \>=6 months after completing a 2-dose primary vaccination with Pfizer BNT162b2, compared to the neutralizing antibody response to the original strain induced by 2-dose primary vaccination with Pfizer BNT162b2; To demonstrate the NI of neutralizing antibody response to the leading variant of high consequence or concern 14 days after booster vaccination with Ad26.COV2.S at the 5\*10\^10 vp dose level, administered \>= 6 months after completing a 2-dose primary vaccination with Pfizer BNT162b2, compared to the neutralizing antibody response to the leading variant of high consequence or concern induced by 2-dose primary vaccination with Pfizer BNT162b2, if feasible.
Conditions Studied
Interventions
- BIOLOGICAL Ad26.COV2.S
Study Locations (20)
Florida
- Velocity Clinical Research, Hallandale Beach — Hallandale
- Research Centers of America, LLC — Hollywood
- Synexus Clinical Research US Inc — Orlando
- Synexus Clinical Research US Inc — The Villages
California
- Anaheim Clinical Trials, LLC — Anaheim
- Ark Clinical Research — Long Beach
- Velocity Clinical Research — North Hollywood
South Carolina
- Velocity Clinical Research, Anderson — Anderson
- Accellacare US Inc — Mt. Pleasant
- Coastal Carolina Research Center — North Charleston
Arizona
- Central Phoenix Medical Clinic — Phoenix
- Synexus Clinical Research US Inc — Tucson
Massachusetts
- Massachusetts General Hospital — Boston
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center — Boston
Illinois
- Optimal Research — Peoria
Kansas
- Johnson County Clin-Trials — Lenexa
Kentucky
- University of Kentucky — Lexington
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 1,541 participants |
| Start Date | 2021-08-06 |
| Est. Completion | 2022-11-22 |
| Phase | Phase 2 |
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Full Details on ClinicalTrials.gov ↗What the Registry Record Tells You About NCT04999111
The ClinicalTrials.gov registry entry for NCT04999111 describes a study currently listed as completed. It is categorized as Phase 2, which is the standard way researchers label where a study sits along the investigational pathway from early safety work through later efficacy and post-marketing evaluation. The registered enrollment target is 1,541 participants, a figure that helps gauge the scale of data the investigators plan to collect. The listed sponsor is Janssen Vaccines & Prevention B.V., which has 9 total studies on file at ClinicalTrials.gov, and sponsors are the parties responsible for study design, oversight, and regulatory filings.
The record links to 1 condition, with Coronavirus Disease appearing as the primary indexed condition, and to 1 intervention — of which Ad26.COV2.S is the first listed. Interventions can include drugs, devices, procedures, behavioral programs, or observational arms, and each is tracked as a separate registry field so that downstream queries can filter accurately. When a trial lists multiple interventions, it usually reflects a multi-arm design or a comparison protocol rather than a single treatment being tested in isolation. The brief summary published in the registry is the clearest source of protocol intent and should be read before drawing conclusions from any sidebar tags.
Geographic footprint matters for practical reasons: NCT04999111 reports 20 study locations spanning 11 distinct geographic areas — top geographies include Florida, California, South Carolina. A larger site network tends to correlate with broader recruitment capacity, but it does not imply anything about study quality, and site-level enrollment status can diverge from the overall registry status shown above. Every data point on this page comes from the public ClinicalTrials.gov dataset and is reproduced here for reference only; it is not a medical recommendation, an endorsement of the sponsor, or an invitation to enroll. Verify current status, eligibility criteria, and contact details directly at ClinicalTrials.gov, and discuss any participation decision with your own healthcare provider.
Frequently Asked Questions
What is clinical trial NCT04999111 about?
NCT04999111 is a clinical study titled "A Study of Ad26.COV2.S Administered as Booster Vaccination in Adults Who Have Previously Received Primary Vaccination With Ad26.COV2.S or BNT162b2". The purposes of this study are to demonstrate the non-inferiority (NI) of the neutralizing antibody response to the original strain 14 days after booster vaccination with Ad26.COV2.S at the different dose levels, administered greater than or equal to (\>=) 6 months after single-dose primary vaccinat...
What is the current status of trial NCT04999111?
This trial is currently completed. It is a Phase 2 study. The enrollment target is 1,541 participants. The study started on 2021-08-06. Estimated completion is 2022-11-22.
What conditions does trial NCT04999111 study?
This clinical trial studies the following conditions: Coronavirus Disease. These conditions were identified from the trial registry and reflect the primary focus areas of the research.
What interventions are being tested in trial NCT04999111?
The interventions under investigation include: Ad26.COV2.S (BIOLOGICAL). Each intervention is being evaluated for safety and efficacy as part of this clinical study.
Who is sponsoring clinical trial NCT04999111?
This trial is sponsored by Janssen Vaccines & Prevention B.V., which has 9 total clinical trials registered on ClinicalTrials.gov. The sponsor is responsible for the study's design, funding, and regulatory compliance.
Where is trial NCT04999111 being conducted?
This trial has 20 study locations across Arizona, California, Florida, Illinois, Kansas. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.
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