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NCT04977479 · ClinicalTrials.gov registry record · Phase 2
The Safety of Administering a Second Dose of a COVID-19 mRNA Vaccine in Individuals Who Experienced a Systemic Allergic Reaction to an Initial Dose
A Phase 2 study, sponsored by National Institute of Allergy and Infectious Diseases (NIAID).
- Completed
- Registry status
- Phase 2
- Development phase
- 20
- Enrollment target
NCT04977479: Completed Phase 2 study, sponsored by National Institute of Allergy and Infectious Diseases (NIAID).
NCT04977479 is a Phase 2 study that has completed, run by National Institute of Allergy and Infectious Diseases (NIAID). The registered enrollment target is 20 participants, below the 133-participant average among 30,622 other Phase 2 trials with a reported enrollment target (85% lower). According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT04977479, a Phase 2 study, has completed, sponsored by National Institute of Allergy and Infectious Diseases (NIAID).
- COMPLETED
- Registry status
- Phase 2
- Development phase
- 20 participants
- Enrollment target
Study Summary
Background: Some people have allergic reactions to COVID-19 mRNA vaccines. Researchers want to learn more about these reactions to provide guidance on who can safely receive the vaccines, including a second dose in people who had a reaction to the first. Objective: To study the safety of giving a second mRNA COVID-19 vaccine dose to people who had a systemic allergic reaction to their first dose. Eligibility: People aged 16-69 who had a systemic allergic reaction to their first dose of COVID-19 vaccine. Design: Individuals who have underlying health issues may need to come to the NIH for screening tests to make sure they are safe to receive the vaccine. People who are eligible to participate in the study will be admitted to the NIH hospital and stay for at least 4 days. They will give urine samples. They will have a nasal swab SARS-CoV-2 test. They will have an intravenous line placed in each arm. They will get the study vaccine (Pfizer-BioNTech COVID-19 vaccine) and one dose of placebo on different days. They will have breathing tests. They may have clinical photography if they develop a rash. Participants will have 4 follow-up visits - 2 by phone and 2 in-person visits at the NIH campus . They will have allergy skin testing at one visit. Drops of different allergens or controls will be placed on their back or arm. The skin under each drop will be scratched with a tool. If the results are negative, a small amount of allergen will be injected just below the surface of their skin. Participants who have no or only a mild allergic reaction to the second dose of the vaccine may be eligible to receive a Booster dose at the NIH. Participation will last for approximately 5 months.
Primary Outcome
Proportion of participants who had recurrent systemic allergic reaction following active COVID-19 vaccine dose in this study. Allergic reactions were graded using Consortium of Food Allergy Research (CoFAR) grading scale (Version 3.0) where Grade 1 (mild) = mild symptoms involving one organ system (skin, conjunctiva, upper respiratory or gastrointestinal); Grade 2 (moderate) = mild symptoms involving ≥2 organ system (skin, conjunctiva, upper respiratory or gastrointestinal); Grade 3 (severe)= mo
Interventions
- OTHER Placebo
- BIOLOGICAL Pfizer-BioNTech COVID-19 Vaccine (Comirnaty)
- BIOLOGICAL Pfizer-BioNTech COVID-19 Vaccine, Bivalent
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 20 participants |
| Start Date | 2021-09-08 |
| Est. Completion | 2023-02-22 |
| Phase | Phase 2 |
What the finished NCT04977479 record still lists
NCT04977479 is an interventional study that assigns participants to a tested intervention. The registry caps enrollment at 20 participants, a relatively small participant target, below the 133-participant average among 30,622 other Phase 2 trials with a reported enrollment target (85% lower).
The record links to 0 conditions, and to 3 interventions - of which Placebo is the first listed.
NCT04977479 does not publish any study locations in the registry export this page uses.
Frequently Asked Questions
What is clinical trial NCT04977479 about?
NCT04977479 is a clinical study titled "The Safety of Administering a Second Dose of a COVID-19 mRNA Vaccine in Individuals Who Experienced a Systemic Allergic Reaction to an Initial Dose". Background: Some people have allergic reactions to COVID-19 mRNA vaccines. Researchers want to learn more about these reactions to provide guidance on who can safely receive the vaccines, including a second dose in people who had a reaction to the first. Objective: To study the safety of giving a...
What is the current status of trial NCT04977479?
This trial is currently completed. It is a Phase 2 study. The enrollment target is 20 participants. The study started on 2021-09-08. Estimated completion is 2023-02-22.
What interventions are being tested in trial NCT04977479?
The interventions under investigation include: Placebo (OTHER), Pfizer-BioNTech COVID-19 Vaccine (Comirnaty) (BIOLOGICAL), Pfizer-BioNTech COVID-19 Vaccine, Bivalent (BIOLOGICAL).
Who is sponsoring clinical trial NCT04977479?
This trial is sponsored by National Institute of Allergy and Infectious Diseases (NIAID), which has 2,006 total clinical trials registered on ClinicalTrials.gov.
Learn More About Clinical Trials
How this trial's enrollment target compares
Where NCT04977479's enrollment target sits among peer trials
20 1805th of 2000 higher than 107 of 2,000 other Phase 2 trials
participants (enrollment target), bucketed by value
Each bar is a band; taller bars hold more other Phase 2 trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov registry export · 2026-08-08
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