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COVID-19 Vaccine-Related eConsults: Case 11

eConsult Clinical Question

A 38-year-old female patient has a history of an anaphylactic reaction to typhoid vaccine. She is currently pregnant and hesitant to get COVID vaccine due to the risk of reaction. I would recommend flu and COVID vaccines in pregnancy, but patient anxious about possible anaphylaxis. Could you confirm that the risk is of an anaphylactic reaction to the COVID vaccine is low?

eConsult Response:  

  1. Patient has a history of a hypersensitivity reaction to possibly the typhoid vaccine and has significant concern in receiving the COVID-19 vaccine. Fortunately, the risk of a hypersensitivity reaction to the COVID-19 vaccine is low with the Pfizer vaccine having an anaphylaxis rate of approximately 2-5 cases per 1 million doses administered. This is similar to other vaccines. In addition, studies have shown that even in patients with a history of allergic reactions to foods, drugs, or previous vaccines (including anaphylaxis), there does not appear to be an increased risk of anaphylaxis with the COVID-19 vaccine.
  2. A recent study in JAMA showed that 98% of highly allergic individuals had no reaction with the COVID-19 vaccine and anaphylaxis occurring in less than 1% (see reference below). The patient should have a full 30-minute observation period after the administration of the vaccine.
  3. In the end, a risk/benefit discussion should take place with shared decision making but the benefits appear to clearly outweigh any risk with receiving the COVID-19 vaccine in this situation.
  4. If primary recommendations do not address the clinical question, I recommend: Formal allergy/immunology consultation. Additional discussion can occur and could consider in-office vaccine challenge.
  5. Reference: Shavit R, Maoz-Segal R, Iancovici-Kidon M, et al. Prevalence of Allergic Reactions After Pfizer-BioNTech COVID-19 Vaccination Among Adults with High Allergy Risk. JAMA Netw Open. 2021;4(8):e2122255. doi:10.1001/jamanetworkopen.2021.22255.

These real-life examples have some limitations. Given the evolving recommendations and guidance on COVID-19 care, these cases should not be considered complete or definitive and may not reflect the most up-to-date guidance.