Answers to burning questions for clinical allergologists related to the new COVID-19 vaccines

Abstract

Background Along with the newly approved vaccines against coronavirus disease 2019 (COVID-19), first reports of allergic or intolerance reactions were published. Subsequently, questions arose whether these vaccines pose an increased risk for intolerance reactions and whether allergic patients may be at higher risk for this. Results Allergic reactions following COVID-19 vaccinations have been reported, but mostly of mild severity and at normal (Moderna®) or only slightly increased frequency (BioNTech/Pfizer®) compared to established conventional vaccines. The risk of allergic reaction to the newly licensed vector vaccines (AstraZeneca®, Johnson&Johnson®) cannot be conclusively assessed yet, but also appears to be low. There is currently no evidence that patients with allergic diseases (atopic patients) react more frequently or more severely to these vaccines. It is currently assumed that intolerance reactions of the immediate-type are either type I allergic (IgE-mediated) reactions or occur via complement activation (CARPA, “complement activation-related pseudoallergy”). Polyethylene glycol (PEG) or polysorbate, which are present as stabilizers in the vaccines, are suspected as triggers for this. Conclusion The data available so far do not show a significantly increased risk of immediate-type allergic reactions in atopic persons. In almost all cases, atopic patients can be vaccinated without problems. Standardized follow-up tests after suspected allergic reactions or CARPA-mediated reactions are currently limited.

COVID-19 Vaccination in Pregnancy, Paediatrics, Immunocompromised Patients, and Persons with History of Allergy or Prior SARS-CoV-2 Infection: Overview of Current Recommendations and Pre- and Post-Marketing Evidence for Vaccine Efficacy and Safety

“…Due to the rarity of severe allergic reactions to COVID-19 vaccination and the not yet elucidated mechanisms underlying those adverse reactions, diagnostic procedures to predict allergic reactions to COVID-19 vaccines are not consistently recommended [120,127]. Because of the hypothesis of a potential contribution of PEG in allergic reactions to COVID-19 mRNA vaccines, some individuals may be offered skin testing for PEG sensitisation before vaccination [120].…”

Olfactory and gustatory disorders in COVID-19

“…Under normal circumstances, psychophysical olfactory and gustatory tests are performed under the guidance of experienced medical personnel (nurses, medical assistants, laboratory personnel) and require personal guidance and supervision. However, during the COVID-19 pandemic, contact avoidance is the order of the day [ 9 , 55 , 56 ].…”

Reações de hipersensibilidade a vacinas

“…In phase III studies, hypersensitivity reactions (urticaria) were rare (1/10,000 to 1/1,000 doses) and anaphylactic reactions were reported, but the frequency could not be estimated from the available data. 56 CoronaVac is an inactivated virus vaccine that contains aluminum hydroxide, disodium hydrogen phosphate, sodium dihydrogen phosphate, sodium chloride, water for injection, and sodium hydroxide. In safety analyses of phase III studies including 5051 participants, 50.8% had adverse events within 7 days of administration, and 40.1% of the reactions were pain at the injection site.…”