Study on allergic reactions after administration of the Pfizer-BioNTech COVID-19 vaccine among adults with high allergy risk


On 31 August, a study was published analyzing the vaccination of patients at high risk for anaphylactic reactions with the Pfizer-BioNTech (BNT162b2) COVID-19 vaccine. This was a prospective cohort study conducted from 27 December 2020 to 22 February 2021, which included 8,102 patients with a history of allergies who underwent a risk assessment at a specialized referral center in Israel. High-risk patients considered "highly allergic" were identified (n = 429), and were immunized under medical supervision. Of the 429 people attended at the COVID-19 referral center and defined as highly allergic, 304 (70.9%) were women and the mean (SD) age was 52 (16) years. After the first dose of the BNT162b2 vaccine, 420 patients (97.9%) had no immediate allergic event, 6 (1.4%) developed minor allergic responses, and 3 (0.7%) had anaphylactic reactions. During the study period, 218 highly allergic patients (50.8%) received the second dose of the BNT162b2 vaccine; of these, 214 (98.2%) had no allergic reactions and 4 patients (1.8%) had minor allergic reactions. Other immediate and late reactions were comparable with those seen in the general population, except for delayed itch and skin eruption, which were more common among allergic patients.

The rate of allergic reactions to the BNT162b2 vaccine was higher among patients with allergies, particularly among a subgroup with a history of high-risk allergies. This study suggests that most patients with a history of allergic diseases and, particularly, highly allergic patients, can be safely immunized using an algorithm that can be implemented in different medical facilities and includes a referral center, a risk assessment questionnaire, and a setting for immunization under medical supervision of highly allergic patients. Further studies are required to define more specific risk factors for allergic reactions to the BNT162b2 vaccine.

Source: 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. 


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