A Review of Anaphylaxis Reactions Following COVID-19 Vaccination, as Reported in the VAERS Database

ABSTRACT

Introduction: The development and approval of COVID-19 vaccines occurred relatively quickly, leading many members of the U.S. population to question their legitimacy and safety. This study aims to evaluate the likelihood of experiencing anaphylaxis after the administration of a COVID-19 in the U.S by considering spontaneous reports of adverse events from the Vaccine Adverse Event Reporting System (VAERS) database. Research Question or Hypothesis: How many patients who received the vaccine suffered anaphylaxis? Study Design: Observational descriptive study. Methods: Our study reviewed the VAERS database's reports of Pfizer/BioNTech, Moderna, and Janssen vaccinations from the date each vaccine was approved through May 2021. The VAERS database systemizes up to five symptoms for each report using the Medical Dictionary for Regulatory Activities (MedDRA). We extracted and analyzed symptoms of anaphylaxis. Results: Out of the of 248,271 reports, 827 individuals, or 0.39%, experienced anaphylaxis. 52.6% of anaphylaxis cases occurred after administration of the Pfizer/BioNTech vaccine, 39.3% occurred after administration of the Moderna vaccine, and 7.9% occurred after administration of the Janssen Vaccine. 66.6% of the reactions occurred after the first dose, while 17.53% occurred after the second dose. The majority of patients who suffered anaphylaxis were female (70.1%). 56.2% of anaphylaxis reactions occurred before or on the third day following administration;1.7% of reactions occurred between 4 and 14 days following administration;and 2.1% of reactions occurred after 14 days following administration. 60.2% of the patients who experienced anaphylaxis were hospitalized and six died. Conclusion: The COVID-19 vaccines were developed in less than a year. The U.S. medical community and population at large have expressed concerns with potential side-effects. The results of this observational study of vaccine-related adverse events, specifically anaphylaxis, resembles those reported in clinical trials.