COVID-19: SARS Vaccination (SARS)


This is a multicenter, randomized, initially blinded (masked), phase 2 trial to assess SARS-CoV-2 vaccination reactions in two populations:

  • One population including individuals with a history of allergic reactions or Mast Cell Disorder (HA/MCD),and
  • One allergy-free population.

Approximately 2040 High-Allergy/Mast Cell Disorder (HA/MCD) and 1360 participants without allergies will be enrolled across participating sites in the United States (3400 total participants). Approximately two-thirds of participants enrolled in each of the 2 groups will be female. This is because the vast majority of cases of anaphylaxis to the COVID-19 vaccines have occurred in women.

Study Duration: Randomized and vaccinated participants will complete study participation in approximately 29 days if vaccinated with the Pfizer-BioNTech COVID-19 Vaccine, 36 days if vaccinated with the Moderna COVID-19 Vaccine, and 50 or 64 days if administered placebo before receiving two doses of either the Pfizer-BioNTech COVID-19 Vaccine or the Moderna COVID-19 Vaccine, respectively.

Total study duration: Approximately 17 weeks.

Summary of Clinical and Study Trial

Background: Allergic reactions have been reported to occur after vaccination with both the Pfizer-BioNTech COVID-19 Vaccine and Moderna COVID-19 Vaccine. Allergic reactions range from mild to severe and include life- threatening anaphylactic reactions, although no deaths have been reported with either vaccine. This study is designed with two principal aims: - To estimate the proportions of systemic allergic reactions to the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 Vaccine in a High-Allergy/Mast Cell Disorder (HA/MCD) population, and - If the risk in the HA/MCD is demonstrable, to determine whether the proportions are higher in the HA/MCD compared to a non-atopic population.


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