Rationale
Patients with confirmed or suspected mast cell activation syndrome (MCAS) often experience anaphylaxis to multiple drugs. Vaccines can exacerbate symptoms associated with mast cell mediator release including urticaria, pruritus, and diarrhea. Whether the US Food and Drug Administration (FDA)-approved COVID-19 vaccines (Pfizer-BioNTech and Moderna mRNA vaccines; Johnson and Johnson/Janssen replication-incompetent adenovirus vaccine) are tolerated in this population is unknown.
Methods
We performed a retrospective study of 300 patients from a single academic center with confirmed or suspected MCAS to determine the proportion receiving at least one dose of a COVID-19 vaccine between December 2020 and November 2021. Among those vaccinated, we assessed for development and duration of vaccine-associated adverse effects.
Results
105/300 patients with confirmed or suspected MCAS received at least one COVID-19 vaccine dose. Reported side effects matched the common side effects described by the US Centers for Disease Control and Prevention: pain, redness, and swelling at the injection site, fever, chills, fatigue, headache, muscle pain, and nausea. Some patients also described neurologic symptoms including orthostatic intolerance, neuropathic pain, and dysautonomia. Few reported immediate onset of symptoms commonly associated with mast cell mediator release like flushing, urticaria, diarrhea, or anaphylaxis. Side effects resolved for most within 21 days or less.
Conclusions
Replication-incompetent adenovirus and mRNA vaccines against COVID-19 are tolerated in patients with suspected or confirmed MCAS. The proportion of these patients fully vaccinated against COVID-19 (35%) is lower than the proportion of fully vaccinated residents in the US (58.4%), suggesting increased vaccine hesitancy among this population, despite COVID-19 vaccine tolerability.
L26