A Study of Ad26.COV2.S Administered as Booster Vaccination in Adults Who Have Previously Received Primary Vaccination With Ad26.COV2.S or BNT162b2
Public ClinicalTrials.gov record NCT04999111. 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 Randomized, Double-blind, Phase 2 Study to Evaluate the Immunogenicity, Reactogenicity and Safety of Ad26.COV2.S Administered as Booster Vaccination in Adults 18 Years of Age and Older Who Have Previously Received Primary Vaccination With Ad26.COV2.S or BNT162b2
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
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.
Study identification
- NCT ID
- NCT04999111
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 1,541 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years and older
- 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 6, 2021 (Actual)
- Primary completion
- Oct 27, 2021 (Actual)
- Completion
- Nov 22, 2022 (Actual)
- Last update posted
- Feb 4, 2025
2021 – 2022
United States locations
- U.S. sites
- 21
- U.S. states
- 12
- U.S. cities
- 20
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Central Phoenix Medical Clinic | Phoenix | Arizona | 85020 | — |
| Synexus Clinical Research US Inc | Tucson | Arizona | 85741 | — |
| Anaheim Clinical Trials, LLC | Anaheim | California | 92801 | — |
| Ark Clinical Research | Long Beach | California | 90815 | — |
| Velocity Clinical Research | North Hollywood | California | 91606 | — |
| Velocity Clinical Research, Hallandale Beach | Hallandale | Florida | 33009 | — |
| Research Centers of America, LLC | Hollywood | Florida | 33024 | — |
| Synexus Clinical Research US Inc | Orlando | Florida | 32806 | — |
| Synexus Clinical Research US Inc | The Villages | Florida | 32162 | — |
| Optimal Research | Peoria | Illinois | 61614 | — |
| Johnson County Clin-Trials | Lenexa | Kansas | 66219 | — |
| University of Kentucky | Lexington | Kentucky | 40536 | — |
| Clinical Trials Management, LLC | Metairie | Louisiana | 70006 | — |
| Massachusetts General Hospital | Boston | Massachusetts | 02114 | — |
| Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center | Boston | Massachusetts | 02215 | — |
| Rochester Clinical Research, Inc | Rochester | New York | 14609 | — |
| Velocity Clinical Research, Anderson | Anderson | South Carolina | 29621 | — |
| Accellacare US Inc | Mt. Pleasant | South Carolina | 29464 | — |
| Coastal Carolina Research Center | North Charleston | South Carolina | 29405 | — |
| Crofoot Research Center | Houston | Texas | 77098 | — |
| Velocity Clinical Research, Salt Lake City | West Jordan | Utah | 84088 | — |
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 NCT04999111, 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 Feb 4, 2025 · Synced Oct 21, 2026
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Open the official record
The complete public registry record, listed eligibility criteria, and available contact information for NCT04999111 live on ClinicalTrials.gov.