Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
Curr Opin Pediatr. 2021 Dec 1;33(6):610-617. doi: 10.1097/MOP.0000000000001077.
A known history of a severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine is the only contraindication to coronavirus disease 2019 (COVID-19) mRNA vaccination. It is important for pediatricians to understand the likelihood of an allergic reaction to COVID-19 mRNA vaccines, including its excipients.
Episodes concerning for anaphylaxis were immediately reported following early administration of COVID-19 mRNA vaccines to adults. Although allergic type symptoms were reported equally in recipients of placebos and test vaccines in phase 3 clinical trials, post-authorization prospective studies state that 0.2-2% of vaccine recipients have experienced allergic reactions. Subsequent allergy testing of affected individuals has focused largely on evaluation of allergic sensitization to a novel vaccine excipient, polyethylene glycol (PEG). PEG is a polymer incorporated in numerous pharmaceutical products because of its favorable, inert properties. The results of allergy testing in adults to date indicate that IgE mediated anaphylaxis to PEG allergy is rarely identified after COVID-19 mRNA vaccine reactions. Numerous individuals with presumed anaphylaxis have tolerated a second vaccine after evaluation and testing by an allergist, suggesting either misdiagnosis or a novel immune mechanism.
Confirmed anaphylactic reactions to COVID-19 mRNA vaccines are rare, likely due to a lack of preexisting IgE against the vaccine components, including PEG.
对疫苗的任何成分有严重过敏反应（例如过敏反应）的已知病史是新型冠状病毒肺炎（COVID-19）mRNA 疫苗接种的唯一禁忌证。儿科医生了解 COVID-19 mRNA 疫苗（包括其赋形剂）发生过敏反应的可能性很重要。
COVID-19 mRNA 疫苗早期接种后，立即报告了疑似过敏反应的病例。尽管在 3 期临床试验中，安慰剂和试验疫苗的接种者报告的过敏样症状发生率相等，但授权后前瞻性研究表明，0.2%-2%的疫苗接种者发生过过敏反应。随后对受影响个体的过敏测试主要集中在评估对新型疫苗赋形剂聚乙二醇（PEG）的过敏致敏情况。PEG 因其有利的惰性特性而被纳入许多药物产品中。迄今为止，对成年人的过敏测试结果表明，在 COVID-19 mRNA 疫苗反应后，很少发现针对 PEG 过敏的 IgE 介导的过敏反应。许多疑似过敏反应的个体在经过过敏症专家的评估和测试后耐受了第二剂疫苗，这表明存在误诊或新的免疫机制。
COVID-19 mRNA 疫苗的确认过敏反应罕见，可能是由于缺乏针对疫苗成分（包括 PEG）的预先存在的 IgE。
