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

Study Description:

This is a single-site study to determine the safety of administering a dose of the Pfizer-BioNTech mRNA coronavirus disease 2019 (COVID-19) vaccine (Comirnaty) to individuals who experienced a systemic allergic reaction to their first full dose of the same vaccine or the Moderna mRNA vaccine, and to investigate possible mechanisms underlying allergic reactions.

Objectives:

Primary Objective:

• Assess the proportion of participants who develop a systemic allergic reaction (Consortium for Food Allergy Research grade 2 reaction and above regardless of tryptase, or CoFAR grade 1 with elevated tryptase [1.2 X baseline plus 2ng/mL]) to the Pfizer-BioNTech COVID-19 vaccine after previously demonstrating a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the same vaccine or the Moderna COVID-19 vaccine.

Secondary Objectives:

• Assess the proportion of participants who develop a severe systemic allergic reaction (CoFAR Grade 3 reaction or higher regardless of tryptase) to the Pfizer-BioNTech COVID-19 vaccine after previously demonstrating a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the same vaccine or the Moderna COVID-19 vaccine.
• Assess the proportion of participants who develop a mild-moderate allergic reaction (CoFAR Grade 1 or 2 reaction regardless of tryptase) to the Pfizer-BioNTech COVID-19 vaccine after previously demonstrating a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the same vaccine or the Moderna COVID-19 vaccine.
• Assess the proportion of participants with anaphylactic reactions (Levels 1-3) per Brighton Collaboration Criteria (see Appendix B) to the Pfizer-BioNTech COVID-19 vaccine after previously demonstrating a systemic allergic reaction (CoFAR Grade 2 or 3 reaction OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the same vaccine or the Moderna COVID-19 vaccine.
• Assess the proportion of participants who develop a systemic allergic reaction (CoFAR Grade 2 reaction or higher regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to the Pfizer-BioNTech COVID-19 vaccine after previously demonstrating a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the same vaccine or the Moderna COVID-19 vaccine compared to the rate of these reactions following placebo administration.
• Compare the severity of allergic reactions to the first dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine to the severity of the reaction following administration of a subsequent dose of the Pfizer-BioNTech vaccine in individuals who experienced a systemic allergic reaction (CoFAR grade 2 reaction and above regardless of tryptase, or CoFAR grade 1 with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine.

Exploratory Objectives:

• Assess the risk of having a systemic allergic reaction to a dose of the Pfizer-BioNTech COVID-19 vaccine in participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the same vaccine or the Moderna COVID-19 according to baseline covariates.
• Examine possible mechanisms of allergic reactions to mRNA-based COVID-19 vaccines.
• Assess innate and adaptive immune responses, including functional antibody levels, to the Pfizer-BioNTech COVID-19 vaccine
• Investigate mental health characteristics of participants who experience an allergic reaction to the COVID-19 vaccine.
• Assess psychological impact of allergic reactions to the COVID-19 vaccine and examine changes in stress levels over time.
• Assess anxiety levels in participants and examine changes in anxiety over time.
• Assess the proportion of participants who experience no reaction or only a mild reaction (CoFAR Grade 2 or below) to a booster dose of the Pfizer-BioNTech vaccine after previously demonstrating a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2 ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine and no allergic reaction or a mild reaction (CoFAR Grade 2 or below) to a subsequent (second) dose of the Pfizer-BioNTech vaccine.
• Assess the development of autoantibodies after COVID-19 vaccination.

Endpoints:<TAB>

Primary Endpoint:

• The proportion of participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine who experience a systemic allergic reaction (CoFAR Grade 2 and above reaction regardless of tryptase, or CoFAR grade 1 with elevated tryptase [1.2 X baseline plus 2ng/mL]) within the 3-hour post-vaccine observation period to a subsequent dose of the Pfizer-BioNTech vaccine.

Secondary Endpoints:

• The proportion of participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine who experience a severe systemic allergic reaction (CoFAR grade 3 reaction and above) within the 3-hour post-vaccine observation period to a subsequent dose of the Pfizer-BioNTech vaccine.
• The proportion of participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine who experience a mild-moderate allergic reaction (CoFAR grade 1 or 2 reaction regardless of tryptase) within the 3-hour post-vaccine observation period to a subsequent dose of the Pfizer-BioNTech vaccine.
• The proportion of participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine who experience an anaphylactic reaction (Levels 1-3) per Brighton Collaboration Criteria within the 3-hour post-vaccine observation period to a subsequent dose of the Pfizer-BioNTech vaccine.
• The proportion of participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine who experience a systemic allergic reaction (CoFAR grade 2 reaction and above regardless of tryptase, or CoFAR grade 1 with elevated tryptase [1.2 X baseline plus 2ng/mL]) within the 3-hour post-vaccine observation period to a subsequent dose of the Pfizer-BioNTech vaccine compared to the rate of these reactions following placebo administration.
• The proportion of participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine who develop a lower or higher grade allergic reaction within the 3-hour post-vaccine observation period to a subsequent dose of the Pfizer-BioNTech vaccine.

Exploratory Endpoints:

• Prevalence of polyethylene glycol (PEG) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in each participant at baseline.
• Changes in anti-PEG and SARS-CoV-2 antibodies in each participant approximately 1 and 5 months after receiving the dose of the Pfizer-BioNTech vaccine administered on study.
• Prevalence of positive skin testing to the vaccine and/or vaccine components including PEG- and polysorbate 80-containing medications.
• Changes in biomarkers from baseline to post-dose of the Pfizer-BioNTech vaccine administered on study (e.g., known mediators of systemic reactions due to mast cell activation, markers of inflammatory response, markers of basophil and neutrophil activation, markers associated with activation of the classical and alternative complement pathways or kinin system, proteomics, metabolomics).
• Changes in blood transcriptomics after vaccination.
• Changes in innate and adaptive immune responses including functional antibody levels after vaccination.
• Mental health/anxiety questionnaire scores and anxiety level ratings at baseline.
• Results of psychiatric consultation/mental health interview.
• Changes in mental health/anxiety questionnaire scores and anxiety level ratings over the study period.
• The proportion of participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2 ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine and no allergic reaction or a mild reaction (CoFAR Grade 2 or below) to a subsequent (second) dose of the Pfizer-BioNTech vaccine who experience no reaction or only a mild reaction (CoFAR Grade 2 or below) to a booster dose of the Pfizer-BioNTech vaccine administered approximately 5 months after the second dose.
• Changes in blood transcriptomics after vaccination.
• Changes in innate and adaptive immune responses including functional antibody levels after vaccination.
• Mental health/anxiety questionnaire scores and anxiety level ratings at baseline.
• Results of psychiatric consultation/mental health interview.
• Changes in mental health/anxiety questionnaire scores and anxiety level ratings over the study period.
• The proportion of participants who previously demonstrated a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless

of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2 ng/mL]) to their first full dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine and no allergic reaction or a mild reaction (CoFAR Grade 2 or below) to a subsequent (second) dose of the Pfizer-BioNTech vaccine who experience no reaction or only a mild reaction (CoFAR Grade 2 or below) to a booster dose of the Pfizer-BioNTech vaccine administered approximately 5 months after the second dose.

• The development of autoantibodies post-second and post-booster doses of the COVID-19 mRNA vaccines.

• INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

• Ability to provide informed consent.
• Stated willingness to comply with all study procedures (including discontinuing medications as needed and availability for the duration of the study.
• Aged 16-69 years.
• Must have experienced a systemic allergic reaction (CoFAR Grade 2 or 3 reaction regardless of tryptase OR Grade 1 reaction with elevated tryptase [1.2 X baseline plus 2 ng/mL] per modified CoFAR Grading Scale for Systemic Allergic Reactions Version 3.0) to the first dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine. Patients without documented hypoxia, hypotension, or evidence of end-organ damage who were treated with epinephrine infusion would be considered as CoFAR Grade 3 reaction and may be eligible per investigator discretion.
• Must be at least 28 days out from their first dose of the Moderna vaccine or 21 days from their first dose of the Pfizer-BioNTech vaccine before proceeding with the placebo or vaccine challenge in this study.
• Have a primary care physician or other health care provider who will manage their medical care outside of this study.

Exclusion criteria

An individual who meets any of the following criteria will be excluded from participation in this study:

• Experienced a Grade 4 systemic allergic reaction (per CoFAR Grading Scale for Systemic Allergic Reactions Version 3.0) to the first dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine.
• Known exposure to SARS-CoV-2 and still within the quarantine window.
• Symptoms consistent with acute COVID-19 infection or known COVID-19 infection (positive reverse transcription-polymerase chain reaction [RT-PCR] or antigen test) and still within the quarantine window
• Have an acute illness, including body temperature greater than 100.4 degrees F, within 14 days prior to enrollment.
• History of autoimmune or other disorders requiring systemic immune modulators.
• Are moderately or severely immunocompromised.
• History of acute urticaria within 28 days prior to enrollment.
• Pregnant.
• Have received any vaccines within 14 days prior to enrollment.
• Scheduled or planned receipt of approved or experimental vaccine prior to visit 3.
• Had any allergen immunotherapy administration within 24 hours prior to the first study vaccination or plan to receive within 24 hours after the second study vaccination.
• Have received a biological therapy within 6 months prior to enrollment.
• Use of systemic steroids for any reason within 28 days prior to enrollment.
• Use of zileuton within 14 days prior to enrollment.
• Use of EUA monoclonal antibodies casirivimab and indevimab, or bamlanivimab, or any other antibody agent for treatment or prevention of COVID-19 within 3 months of randomization.
• Presence of condition(s) that, in the judgment of the investigator or the referring physician, may put the participant at undue risk or make them unsuitable for participation in the study.