Since the beginning of the
COVID-19 pandemic,
vaccines have been developed to mitigate the spread of SARS-CoV-2, the virus that causes
COVID-19. These
vaccines have been effective in reducing the rate and severity of
COVID-19 infection but also have been associated with various adverse events (AEs). In this study, data from the
Vaccine Adverse Event Reporting System (VAERS) was queried and analyzed via the Cov19VaxKB
vaccine safety statistical analysis tool to identify statistically significant (i.e., enriched) AEs for the three currently FDA-authorized or approved
COVID-19 vaccines. An ontology-based classification and literature review were conducted for these enriched AEs. Using VAERS data as of 31 December 2021, 96 AEs were found to be statistically significantly associated with the Pfizer-BioNTech, Moderna, and/or Janssen
COVID-19 vaccines. The Janssen
COVID-19 vaccine had a higher crude reporting rate of AEs compared to the Moderna and Pfizer
COVID-19 vaccines. Females appeared to have a higher case report frequency for top adverse events compared to males. Using the Ontology of Adverse Event (OAE), these 96 adverse events were classified to different categories such as behavioral and neurological AEs, cardiovascular AEs, female reproductive system AEs, and immune system AEs. Further statistical comparison between different ages, doses, and sexes was also performed for three notable AEs:
myocarditis, GBS, and
thrombosis. The Pfizer
vaccine was found to have a closer association with
myocarditis than the other two
COVID-19 vaccines in VAERS, while the Janssen
vaccine was more likely to be associated with
thrombosis and GBS AEs. To support standard AE representation and study, we have also modeled and classified the newly identified
thrombosis with
thrombocytopenia syndrome (TTS) AE and its subclasses in the OAE by incorporating the Brighton Collaboration definition. Notably, severe
COVID-19 vaccine AEs (including
myocarditis, GBS, and TTS) rarely occur in comparison to the large number of
COVID-19 vaccinations administered in the United States, affirming the overall safety of these
COVID-19 vaccines.