The role of co-morbidities in the development of an AEFI after COVID-19 vaccination in a large prospective cohort with patient-reported outcomes in the Netherlands.

BACKGROUND: The effect of a preexisting comorbidity on the occurrence of adverse events after immunization (AEFIs) has been studied poorly. In this longitudinal cohort study, we assess the association between co-morbidities and the occurrence of AEFIs after COVID-19 vaccination. Also, we described the occurrence of flare-ups and their manifestation after COVID-19 vaccination in people with rheumatic diseases. RESEARCH DESIGN AND METHODS: We performed multivariable logistic regression to investigate the association between the occurrence of AEFIs and 10 common comorbidities using patient-reported data from people vaccinated with the AstraZeneca, Johnson&Johnson, Moderna or Pfizer vaccine. RESULTS: Occurrence of any AEFI, injection site reactions, headache, fatigue and/or malaise was significantly associated with presence of comorbidities, including psychological disorders, musculoskeletal disorders, and endocrine disorders after the first and second dose (OR ranges 1.23-1.77). One participant with rheumatoid arthritis experienced a flare-up after receiving the first dose of the AstraZeneca vaccine. DISCUSSION/CONCLUSION: The results showed that the odds of reporting an AEFI after COVID-19 vaccination is significantly higher in the presence of some comorbidities whilst flare-ups are uncommon after receiving COVID-19 vaccination in people with rheumatic disease. In-depth research is needed to validate our results and unravel the observed associations from a mechanistic perspective.