Cureus. 2026 Apr 30;18(4):e108030. doi: 10.7759/cureus.108030. eCollection 2026 Apr.
ABSTRACT
Background and aim COVID-19 mRNA vaccines were granted Emergency Use Authorization by the United States FDA in December 2020. Serious adverse events following immunization (AEFI) with COVID-19 vaccines started to be seen by clinicians soon after the vaccines were available to the public. The objective of this study is to report the clinical course of patients with adverse events following COVID-19 vaccination encountered in medical practice. Methods These cases (age range, 18-82 years) were prospectively identified and collected by the authors during formal or informal consultation from January to December 2021. Cases were excluded from further consideration for AEFI with COVID-19 vaccines if an alternative explanation was deemed more likely at the time of consultation. The authors did not solicit medical providers, patients, or the public, nor screen medical records for adverse events following COVID-19 vaccination. This is a descriptive case series; therefore, no statistical analysis was performed. Results We encountered 18 patients with AEFI, nine (50%) males (range, 22-78 years) and nine (50%) females (range, 18-82 years). Clinical presentations involved various organ systems, including cardiovascular (five), nervous system (five), immune system/hematologic (four), skin (one), gastrointestinal (one), pulmonary (one), and infection (two). This paper details their clinical courses. Conclusions We encountered a variety of AEFI, including myocarditis, demyelinating disease, encephalitis, Bell's palsy, burning mouth syndrome, multisystem inflammatory syndrome, immune thrombocytopenia, pneumonitis, colitis, staphylococcal infection, and erythromelalgia. This detailed case series was presented to help clinicians consider a diagnosis of AEFI for patients when no other explanation has been found after a thorough diagnostic evaluation. These described adverse events following COVID-19 vaccination do not imply causality. We hope this descriptive case series leads to further case-control studies from healthcare organizations to explore the possible risks, incidence, and causal relationships of such adverse events following COVID-19 vaccination.
PMID:42220848 | PMC:PMC13222021 | DOI:10.7759/cureus.108030