According to a recent presentation at the 2022 American Academy of Allergy, Asthma, & Immunology Annual Meeting, replication-incompetent adenovirus and mRNA vaccines against COVID-19 are tolerated among patients with confirmed or suspected mast cell activation syndrome (MCAS).

Lead study author Jessica D Macdougall, MD, University of North Carolina at Chapel Hill, and colleagues explained patients with MCAS are prone to anaphylaxis with multiple drugs and vaccinations can exacerbate symptoms associated with mast cell mediator release including urticaria, pruritus, and diarrhea.

A retrospective study of 300 patients with confirmed or suspected MCAS in a single academic center between December 2020 and November 2021 was conducted. Results show that 105 of 300 patients received at least 1 COVID-19 vaccine does—of either Pfizer-BioNTech, Moderna mRNA vaccines; or Johnson and Johnson/Janssen replication-incompetent adenovirus vaccine.

The side effects reported by the patient cohort were similar to the common side effects described by the US Centers for Disease Control and Prevention and included pain, redness, and swelling at the injection site, fever, chills, fatigue, headache, muscle pain, and nausea.

A portion of patients reported neurological side effects such as orthostatic intolerance, neuropathic pain, and dysautonomia.

Only a few patients experienced immediate onset of symptoms commonly associated with mast cell mediator release like flushing, urticaria, diarrhea, or anaphylaxis—and in most cases, these symptoms were resolved within 21 days.

“What this shows us is that both replication-incompetent adenovirus and mRNA vaccines for COVID-19 can be tolerated in patients with suspected or confirmed MCAS,” said primary author Dr Macdougall. “Despite this, only 35% of these patients are fully vaccinated against COVID-19 compared to 58.4% of the general US population. It’s important we share this with patients to make them aware that it is possible to safely be vaccinated, as long as a discussion of the risks and benefits is had with their health care provider.” 

References:

1. Macdougall J, Amelio C, Kwan M, Iweala O. Tolerability of COVID-19 vaccination in patients with mast cell activation. Presented at: 2022 AAAAI Annual Meeting; February 25-28, 2022; Phoenix, AZ.
2. COVID-19 Vaccination Well-Tolerated In Patients With Mast Cell Activation Syndrome. News release. American Academy of Allergy, Asthma, & Immunology. February 1, 2022. Accessed March 10, 2022.