ABSTRACT
Background: Since the introduction of COVID-19 vaccines, many reports have focused on adverse reactions. However, there is no global agreement on how to manage those patients. We aim to assess the management of adverse reactions by an immunoallergology department and its outcomes. Method(s): Retrospective analysis of the patients sent to our centre from January to October 2021 for adverse reactions to a COVID-19 vaccine, and who were considered ineligible for a 2nd dose by general practitioners. We collected data on the reported reactions, allergological study and outcomes. Result(s): 123 patients with adverse reactions were included (77% women, n = 95), mean age 55 years-old (min 12;max 92). Pfizer/ BioNTech Vaccine was inoculated in 64 patients (52%);Moderna in 15 (12%);AstraZeneca in 44 (36%). 65 patients (53%) presented symptoms compatible with allergic reactions: 86% (n = 56) with mucocutaneous symptoms, mainly urticaria-like lesions and/or angioedema;17% (n = 11) with suspected anaphylaxis and 5% (n = 3) with Steven-Johnson Syndrome. 19 patients performed skin testing with: PEG2000 (n = 17);polysorbate 80 (n = 15);COVID-19 vaccines (n = 21). Four patients had at least one positive test. 58 patients (47%) presented with non-allergic reactions. They showed great variability of symptoms. Most mild: 47% reported non-specific symptoms (such as malaise, headache, myalgia, fever, or fatigue) and 26% reported local reactions on the inoculation site. Some severe: 6 with deep vein or pulmonary thrombosis, 4 with myocarditis, 2 with stroke or myocardial infarction, and 1 with VITT. Patients with positive skin tests or severe previous reactions (n = 36, 29%) were referred for an alternative vaccine. Those with suspected allergic reaction but negative skin tests were premedicated with antihistamines before the 2nd dose. Follow-up showed: of the 81 patients (66%) who received an additional dose, 25% (n = 20) reported an adverse reaction, which was mild, and no case of anaphylaxis was reported. 16 (13%) refused a 2nd dose, and for 26 (21%) the information could not be obtained. Conclusion(s): The intervention of an allergologist had a significant positive impact on vaccination rates, with 2/3 of patients being reclassified as eligible for a 2nd dose. Allergological study and intervention identified vaccine-allergic patients and guided the decision on vaccine change and premedication, which resulted in a considerably lower number of adverse reactions to the 2nd dose, or at least its severity.
ABSTRACT
Background: COVID-19 virus vaccines are associated with adverse events. We aim to characterize and compare adverse reactions to different COVID-19 vaccines in a Portuguese centre. Method(s): Retrospective analysis of patients with adverse reactions to COVID-19 vaccines referred to our Immunoallergology Department between January and October 2021. The patients were divided according to the vaccine used: Pfizer/BioNTech (Pf), Moderna (M), or AstraZeneca (AZ). Result(s): 123 patients were included. 64 patients (52%) reacted to the Pf vaccine (77% women, mean age 49 years old);15 (12%) to the M vaccine (87% females, mean age 50 years old);and 44 (36%) to the AZ vaccine (75% women, mean age 64.8 years old). All groups showed a higher number of non-immediate reactions (>6h after inoculation): 59% for Pf, 60% for M, and 91% for AZ. Reactions to Pf and M were more frequently allergic-like (63% and 60%, respectively). Reactions to AZ were predominantly non-allergic (64%). The most frequently reported reactions for Pf and M were: sensation of throat tightness (Pf 31%, M 20%), urticaria (Pf 30%, M 27%), angioedema (Pf 17%, M 33%), constitutional non-specific symptoms (Pf 25%, M 27%), and local reactions on the inoculation site (Pf 20%, M 33%). There were 8 (13%) patients with suspected anaphylaxis with Pf, 3 (20%) with M, and none with AZ. The most frequently reported reactions for AZ were cardiovascular events (30%): myocardial, cerebral or pulmonary thromboembolic events (n = 6), phlebitis (n = 5), myocarditis (n = 1), and vaccine-induced immune thrombotic thrombocytopenia (n = 1). Other common reactions were constitutional non-specific symptoms (32%), local reactions on the inoculation site (18%), urticaria (23%), angioedema (14%), and non-urticaria rash (14%). Conclusion(s): Adverse reactions were more common in women. The mRNA vaccines were more frequently associated with allergic-like reactions, including anaphylaxis. In contrast, AZ vaccine was associated with nonallergic cardiovascular reactions. Up to 1/3 of patients in each group reported constitutional non-specific symptoms and local reactions on the inoculation site.