COVID-19Phase 4NCT05212610
Assessing Safety of Coronavirus Infection (COVID-19) Messenger RNA (mRNA) Vaccine Administration in the Setting of a Previous Adverse Reaction
A Phase 4 study testing Pfizer-BioNTech mRNA COVID-19 vaccine and Moderna mRNA COVID-19 vaccine in people with COVID-19 and Corona Virus Infection, run by University of Michigan at 1 site in United States.
Trial summary
This study will evaluate the safety of administering an additional dose of an mRNA COVID-19 vaccine or mRNA bivalent COVID-19 booster vaccine to individuals who have had adverse reactions to a previous dose or administering an initial dose of an mRNA COVID-19 vaccine to individuals with a personal history of allergic… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- COVID-19, Corona Virus Infection
- What is being tested?
- Pfizer-BioNTech mRNA COVID-19 vaccine and Moderna mRNA COVID-19 vaccine
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 137 participants
- Where
- 1 siteUnited States
- Study dates
- 21 Mar 2022to 7 Mar 2025
- Phase
- Phase 4
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age over 18.
- Participant must be able to understand and provide informed consent
- No evidence of infectious illness (defined as fever >38⁰C, vomiting, diarrhea, new cough, new shortness of breath, new congestion, new runny nose, new headache or sore throat) within 14 days of vaccine administration.
- Subjects must have a history of adverse reaction to either the Pfizer-BioNTech mRNA COVID vaccination or the Moderna mRNA COVID vaccination, a personal history of allergic reaction without prior mRNA COVID vaccination, or a history of adverse reaction to natural COVID infection.
- Females of childbearing potential must have a negative pregnancy test prior to vaccination.
Who cannot join
- Under age 18
- Inability or unwillingness of a participant to give written informed consent
- Evidence of COVID-19 infection within 21 days of vaccination visit
- History of antibody agent or convalescent plasma for treatment or prevention of COVID-19 within 90 days
- Individuals with known history of a severe allergic reaction (e.g., anaphylaxis) to any component of the Pfizer-BioNTech mRNA COVID-19 vaccination or the Moderna mRNA COVID-19 vaccination.
- History of underlying immune disorder.
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- Pregnancy
- Immunocompromised
- Persons with primary or acquired immunodeficiency
- Persons on anti-rejection therapy following solid organ transplant or bone marrow transplant
- Persons on biologic therapeutic agents
- Persons with malignancy and ongoing or recent chemotherapy
- Persons receiving systemic immunosuppressive therapy, including corticosteroids equivalent to 20 mg/day of prednisone for 2 weeks
- Persons with chronic kidney disease stage 3 or higher
- Persons with history of significant pulmonary compromise
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Assessing Safety of COVID-19 mRNA Vaccine Administration in the Setting of a Previous Adverse Reaction
This study will evaluate the safety of administering an additional dose of an mRNA COVID-19 vaccine or mRNA bivalent COVID-19 booster vaccine to individuals who have had adverse reactions to a previous dose or administering an initial dose of an mRNA COVID-19 vaccine to individuals with a personal history of allergic reaction. In addition, this study will evaluate the safety of administering an initial or additional dose or bivalent booster of an mRNA COVID-19 vaccine to individuals experiencing an adverse reaction to a natural COVID-19 infection ("long COVID").
Eligible participants enrolled in this trial will receive an initial or additional dose of either the Pfizer-BioNTech COVID-19 bivalent vaccine or the Moderna COVID-19 bivalent vaccine. Participants will also be required to have 1-2 in person visits along with phone call follow up visits.
Read more
We hypothesize that individuals who have had adverse reactions to a previous dose of an mRNA COVID-19 vaccine will tolerate an additional dose of the primary mRNA vaccine or bivalent booster, as indicated, and those with a personal history of allergic reaction will tolerate an initial dose of an mRNA COVID-19 vaccine. We also hypothesize that those individuals experiencing an adverse reaction will tolerate an initial or additional dose of a primary mRNA COVID-19 bivalent vaccine, as indicated.
The study hypothesizes that individuals that have had adverse reactions to a dose of an mRNA COVID-19 vaccine will tolerate an additional dose and those with a personal history of allergic reaction will tolerate vaccination with an mRNA COVID-19 vaccine.
- Conditions
- COVID-19, Corona Virus Infection
- Being tested
- Pfizer-BioNTech mRNA COVID-19 vaccine, Moderna mRNA COVID-19 vaccine
- Keywords
- mRNA vaccine, Adverse reactions, Vaccine re-challenge, Allergic reactions, Long COVID infection
- Medical subject headings
- COVID-19, Coronavirus Infections, Hypersensitivity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pfizer-BioNTech mRNA COVID-19 vaccineBiological
Also called Comirnaty
Participants will receive an initial or additional dose of a highly protective COVID-19 mRNA vaccine for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in an environment where the investigators and staff are experienced in the care of patients with allergic reactions.
Moderna mRNA COVID-19 vaccineBiological
Participants will receive an initial or additional dose of a highly protective COVID-19 mRNA vaccine for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in an environment where the investigators and staff are experienced in the care of patients with allergic reactions.
| Study group | Role | What they receive |
|---|---|---|
| Pfizer-BioNTech mRNA COVID-19 vaccine | Experimental | Subject will receive an initial or additional dose of the Pfizer-BioNTech (Comirnaty) mRNA COVID-19 vaccine Receives: Biological: Pfizer-BioNTech mRNA COVID-19 vaccine |
| Moderna mRNA COVID-19 vaccine | Experimental | Subject will receive an initial or additional dose of the Moderna mRNA COVID-19 vaccine Receives: Biological: Moderna mRNA COVID-19 vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Participants Who Had a Reaction to an Initial or Additional Dose of the Pfizer-BioNTech or Moderna COVID-19 mRNA Vaccine, or Who Had Long COVID
Results reflect the number of participants who had previously received the Pfizer-BioNTech, the Moderna mRNA COVID-19 vaccine, or both, and who had experienced an adverse reaction (AR). An AR would be any symptom reported or objective finding during the 30-minute observation, or any symptom reported at the 7 day follow up. ARs were graded using the FDA Guidance for Industry Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials, which utilized the following grades:
Grade 1 = Mild Grade 2 = Moderate Grade 3 = Severe Grade 4 = Life-threatening Grade 5 = Death
Measured: up to approximately 7 days after the vaccine is given
Number of Participants With Treatment-related Allergic Reaction Adverse Events
The safety of administering an initial or additional dose will be determined by using the grading of systemic allergic reactions will be based on a scale of 1 (mild reaction) to 5 (severe reaction, including death) according to criteria set forth in the Consortium of Food Allergy Research (CoFAR) grading scale (version 3.0) modified for adults as well as the Brighton Collaboration to grade the diagnostic certainty of anaphylaxis. Results reflect the number of participants who received an initial dose or were revaccinated during the trial, and experienced related acute allergic reaction adverse event, and what the CoFAR severity for the events was. Events were deemed to be allergic if symptoms were consistent with an IgE-reaction and symptom onset began within 1 hour of vaccination.
Measured: up to approximately 7 days after the vaccine is given
Secondary outcomes (1)
Number of Non-allergic Clinical Adverse Reactions
Results reflect the number of participants who experienced a non-allergic clinical adverse reaction (AR). A non-allergic clinical AR was determined by non-allergic symptomatology and time frame from when the participant received a vaccine. Nonallergic ARs were symptoms that were inconsistent with an IgE-mechanism or had an onset greater than 1 hour following vaccination. ARs were graded using the FDA Guidance for Industry Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials, which utilized the following grades: Grade 1 = Mild Grade 2 = Moderate Grade 3 = Severe Grade 4 = Life-threatening Grade 5 = Death
Measured: up to approximately 7 days after the vaccine is given
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jan 2022
- Study start21 Mar 2022
- Primary completion7 Mar 2025
- Study completion7 Mar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for COVID-19Studies of the same condition, open and under way.
- More trials run by University of MichiganThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 137 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Michigan
- Sponsor type
- University, hospital or other
- Collaborators
- The Wallace Foundation
- Responsible party
- Principal investigator, James Baker Jr MD, University of Michigan
- Investigators
- James Baker, MD, Principal investigator, University of Michigan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05212610
- Sponsor's protocol ID
- HUM00206480
- Status last verified
- Apr 2025
- First submitted
- 26 Jan 2022
- Last updated
- 27 Mar 2026
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessing Safety of COVID-19 mRNA Vaccine Administration in the Setting of a Previous Adverse Reaction
- ClinicalTrials.gov ID
- NCT05212610
- Acronym / sponsor ID
- HUM00206480
- Conditions
- COVID-19, Corona Virus Infection
- Keywords
- mRNA vaccine, Adverse reactions, Vaccine re-challenge, Allergic reactions, Long COVID infection
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 137 participants (actual)
- Lead sponsor
- University of MichiganUniversity, hospital or other
- Collaborators
- The Wallace Foundation
- Study start
- 21 Mar 2022 (actual)
- Primary completion
- 7 Mar 2025 (actual)
- Study completion
- 7 Mar 2025 (actual)
- First posted
- 28 Jan 2022 (actual)
- Results
- Posted 27 Mar 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will evaluate the safety of administering an additional dose of an mRNA COVID-19 vaccine or mRNA bivalent COVID-19 booster vaccine to individuals who have had adverse reactions to a previous dose or administering an initial dose of an mRNA COVID-19 vaccine to individuals with a personal history of allergic reaction. In addition, this study will evaluate the safety of administering an initial or additional dose or bivalent booster of an mRNA COVID-19 vaccine to individuals experiencing an adverse reaction to a natural COVID-19 infection ("long COVID").
Eligible participants enrolled in this trial will receive an initial or additional dose of either the Pfizer-BioNTech COVID-19 bivalent vaccine or the Moderna COVID-19 bivalent vaccine. Participants will also be required to have 1-2 in person visits along with phone call follow up visits.
We hypothesize that individuals who have had adverse reactions to a previous dose of an mRNA COVID-19 vaccine will tolerate an additional dose of the primary mRNA vaccine or bivalent booster, as indicated, and those with a personal history of allergic reaction will tolerate an initial dose of an mRNA COVID-19 vaccine. We also hypothesize that those individuals experiencing an adverse reaction will tolerate an initial or additional dose of a primary mRNA COVID-19 bivalent vaccine, as indicated.
The study hypothesizes that individuals that have had adverse reactions to a dose of an mRNA COVID-19 vaccine will tolerate an additional dose and those with a personal history of allergic reaction will tolerate vaccination with an mRNA COVID-19 vaccine.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Pfizer-BioNTech mRNA COVID-19 vaccine | Experimental | Biological: Pfizer-BioNTech mRNA COVID-19 vaccineSubject will receive an initial or additional dose of the Pfizer-BioNTech (Comirnaty) mRNA COVID-19 vaccine |
| Moderna mRNA COVID-19 vaccine | Experimental | Biological: Moderna mRNA COVID-19 vaccineSubject will receive an initial or additional dose of the Moderna mRNA COVID-19 vaccine |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age over 18.
- Participant must be able to understand and provide informed consent
- No evidence of infectious illness (defined as fever >38⁰C, vomiting, diarrhea, new cough, new shortness of breath, new congestion, new runny nose, new headache or sore throat) within 14 days of vaccine administration.
- Subjects must have a history of adverse reaction to either the Pfizer-BioNTech mRNA COVID vaccination or the Moderna mRNA COVID vaccination, a personal history of allergic reaction without prior mRNA COVID vaccination, or a history of adverse reaction to natural COVID infection.
- Females of childbearing potential must have a negative pregnancy test prior to vaccination.
Key exclusion criteria (15 listed)
- Under age 18
- Inability or unwillingness of a participant to give written informed consent
- Evidence of COVID-19 infection within 21 days of vaccination visit
- History of antibody agent or convalescent plasma for treatment or prevention of COVID-19 within 90 days
- Individuals with known history of a severe allergic reaction (e.g., anaphylaxis) to any component of the Pfizer-BioNTech mRNA COVID-19 vaccination or the Moderna mRNA COVID-19 vaccination.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Pfizer-BioNTech mRNA COVID-19 vaccineAlso: ComirnatyParticipants will receive an initial or additional dose of a highly protective COVID-19 mRNA vaccine for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in an environment where the investigators and staff are experienced in the care of patients with allergic reactions. | Biological | Pfizer-BioNTech mRNA COVID-19 vaccine |
| Moderna mRNA COVID-19 vaccineParticipants will receive an initial or additional dose of a highly protective COVID-19 mRNA vaccine for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in an environment where the investigators and staff are experienced in the care of patients with allergic reactions. | Biological | Moderna mRNA COVID-19 vaccine |
Primary outcome
Participants Who Had a Reaction to an Initial or Additional Dose of the Pfizer-BioNTech or Moderna COVID-19 mRNA Vaccine, or Who Had Long COVID
Time frame: up to approximately 7 days after the vaccine is given
Results reflect the number of participants who had previously received the Pfizer-BioNTech, the Moderna mRNA COVID-19 vaccine, or both, and who had experienced an adverse reaction (AR). An AR would be any symptom reported or objective finding during the 30-minute observation, or any symptom reported at the 7 day follow up. ARs were graded using the FDA Guidance for Industry Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials, which utilized the following grades: Grade 1 = Mild Grade 2 = Moderate Grade 3 = Severe Grade 4 = Life-threatening Grade 5 = Death
Number of Participants With Treatment-related Allergic Reaction Adverse Events
Time frame: up to approximately 7 days after the vaccine is given
The safety of administering an initial or additional dose will be determined by using the grading of systemic allergic reactions will be based on a scale of 1 (mild reaction) to 5 (severe reaction, including death) according to criteria set forth in the Consortium of Food Allergy Research (CoFAR) grading scale (version 3.0) modified for adults as well as the Brighton Collaboration to grade the diagnostic certainty of anaphylaxis. Results reflect the number of participants who received an initial dose or were revaccinated during the trial, and experienced related acute allergic reaction adverse event, and what the CoFAR severity for the events was. Events were deemed to be allergic if symptoms were consistent with an IgE-reaction and symptom onset began within 1 hour of vaccination.
1 secondary outcome
Number of Non-allergic Clinical Adverse Reactions
Time frame: up to approximately 7 days after the vaccine is given
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Mar 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
James Baker, MD principal investigator
University of Michigan
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Pfizer-BioNTech mRNA COVID-19 vaccine and Moderna mRNA COVID-19 vaccine in people with COVID-19 and Corona Virus Infection, run by University of Michigan at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 27 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 27 Mar 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Participants Who Had a Reaction to an Initial or Additional Dose of the Pfizer-BioNTech or Moderna COVID-19 mRNA Vaccine, or Who Had Long COVID (time frame: up to approximately 7 days after the vaccine is given). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Mar 2026.