# COVID19 SARS Vaccinations: Systemic Allergic Reactions to SARS-CoV-2 Vaccinations

> **NCT04761822** · PHASE2 · COMPLETED · sponsor: **National Institute of Allergy and Infectious Diseases (NIAID)** · enrollment: 746 (actual)

## Conditions studied

- SARS-CoV Infection
- COVID-19
- Allergic Reaction
- Mast Cell Disorder

## Interventions

- **BIOLOGICAL:** Moderna COVID-19 Vaccine
- **BIOLOGICAL:** Pfizer-BioNTech COVID-19 Vaccine
- **BIOLOGICAL:** Placebo

## Key facts

- **NCT ID:** NCT04761822
- **Lead sponsor:** National Institute of Allergy and Infectious Diseases (NIAID)
- **Sponsor class:** NIH
- **Phase:** PHASE2
- **Study type:** INTERVENTIONAL
- **Status:** COMPLETED
- **Start date:** 2021-04-07
- **Primary completion:** 2022-04-20
- **Final completion:** 2022-04-27
- **Target enrollment:** 746 (ACTUAL)
- **Last updated:** 2025-08-12

## Collaborators

- [object Object]
- [object Object]

## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT04761822

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT04761822, "COVID19 SARS Vaccinations: Systemic Allergic Reactions to SARS-CoV-2 Vaccinations". Retrieved via AI Analytics 2026-07-05 from https://api.ai-analytics.org/clinical/NCT04761822. Licensed CC0.

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