Allergic Reactions to COVID-19 Vaccines: Risk Factors, Frequency, Mechanisms and Management.

Conventional vaccines have been widely studied, along with their risk of causing allergic reactions. These generally consist of mild local reactions and only rarely severe anaphylaxis. Although all the current COVID-19 vaccines marketed in Europe have been shown to be safe overall in the general population, early post-marketing evidence has shown that mRNA-based vaccines using novel platforms (i.e., lipid nanoparticles) were associated with an increased risk of severe allergic reactions as compared to conventional vaccines. In this paper we performed an updated literature review on frequency, risk factors, and underlying mechanisms of COVID-19 vaccine-related allergies by searching MEDLINE and Google Scholar databases. We also conducted a qualitative search on VigiBase and EudraVigilance databases to identify reports of "Hypersensitivity" and "Anaphylactic reaction" potentially related to COVID-19 vaccines (Comirnaty, Spikevax, Vaxzevria and COVID-19 Janssen Vaccine), and in EudraVigilance to estimate the reporting rates of "Anaphylactic reaction" and "Anaphylactic shock" after COVID-19 vaccination in the European population. We also summarized the scientific societies' and regulatory agencies' recommendations for prevention and management of COVID-19 vaccine-related allergic reactions, especially in those with a history of allergy.

Clinical and quality of life assessment in patients with latex allergy during COVID-19 pandemic: Possible protective role of continuous latex immunotherapy.

Introduction: During COVID-19 pandemic, the massive use of Personal Protective Equipment could provoke severe adverse reactions in latex allergy patients and could negatively affect their quality of life. Methods: Trough a survey the study aimed: (a) to evaluate the incidence of allergic reactions in patients with latex allergy during the SARS-CoV-2 pandemic; (b) to evaluate the protective role of continuous latex sublingual immunotherapy (SLIT) during this period; and (c) to evaluate quality of life of natural rubber latex allergy (NRLA) patients during the pandemic. Results: 67 patients (9 males and 58 females, mean age of 45.9 ± 11.4 years) suffering from latex allergy were included in the present study. We recorded among our patients 13 cases (34.2%) of urticarial/angioedema (U/A), 9 cases (23.6%) of respiratory symptoms (dyspnoea, shortness of breath and wheezing) and 7 cases (18.4%) of anaphylaxis. In patients who underwent continuous SLIT, we observed less cases of U/A (p < 0.001), respiratory symptoms (p < 0.001), anaphylaxis (p = 0.003), hospitalizations (p = 0.014) and a lower therapy administration. We compared the results of SF-36 questionnaire in patients who underwent continuous and not-continuous SLIT with a significance differences score between these two groups. Conclusions: Our study is the first that investigated the clinical and quality of life effects of COVID-19 pandemic in NRLA patients.

The Revenge of Unintended Consequences of Anaphylaxis-Risk Overdiagnosis: How Far We Have Come and How Far We Have to Go.

Overdiagnosis of anaphylaxis risk is an underappreciated aspect of anaphylaxis prevention. Whereas the benefits of anaphylaxis-risk prevention are well known, potential harms resulting from preemptive approaches to mitigate anaphylaxis-risk are not insignificant. Still, great progress has been made in recent years to avoid the unintended consequences of anaphylaxis-risk overdiagnosis. Reflection on recent advances in the use of diagnostic testing, as well as the application of diagnostic labels, provides an important perspective to understand how far the specialty of allergy and immunology has come in improving the lives of patients and families. Examples of recent paradigm shifts in anaphylaxis-risk management include approaches to peanut allergy prevention without screening, deferral of corticosteroids to prevent biphasic anaphylaxis reactions, reevaluation of reflex use of emergency medical services for resolved community anaphylaxis, and an approach to penicillin allergy delabeling with direct oral challenge. Routine medical practices to decrease anaphylaxis risk can have lifelong impacts for patients-beyond just preventing anaphylaxis. As our understanding of these trade-offs evolves, it becomes necessary to weigh both the benefits and the harms of past management approaches. Because medicine remains a science of uncertainty and an art of probability, a critical approach to risk mitigation remains necessary to find the often-elusive balance in anaphylaxis prevention.

Allergic reactions and adverse events associated with administration of mRNA-based vaccines. A health-care system experience.

Background: Adverse reactions, including anaphylaxis, to messenger RNA coronavirus disease 2019 (COVID-19) vaccines rarely occur. Because of the need to administer a timely second dose in subjects who reported a reaction to their first dose, a panel of health-care professionals developed a safe triage of the employees and health care providers (EHCP) at a large health-care system to consider administration of future dosing. Methods: There were 28,544 EHCPs who received their first dose of COVID-19 vaccines between December 15, 2020, and March 8, 2021. The EHCPs self-reported adverse reactions to a centralized COVID-19 command center (CCC). The CCC screened and collected information on the quality of reaction, symptoms, and timing of the onset of the reaction. Results: Of 1253 calls to the CCC, 113 were identified as requiring consideration by a panel of three (American Board of Allergy and Immunology) ABAI-certified allergists for future dosing or formal in-person assessment. Of the 113 EHCPs, 94 (83.2%) were recommended to get their second dose. Eighty of 94 received their second planned dose without a severe or immediate reaction. Of the 14 of 113 identified as needing further evaluation, 6 were evaluated by a physician and subsequently received their second dose without a serious adverse reaction. Eight of 14 did not receive their second dose. Only 5 of the 113 EHCPs reported reactions (4.4%) were recommended to not take the second dose: 3 (2.6%) because of symptoms consistent with anaphylaxis, and 2 because of neurologic complications (seizure, stroke). Conclusion: The panel demonstrated that, by consideration of reaction history alone, the ECHPs could be appropriately triaged to receive scheduled second dosing of COVID-19 vaccines without delays for in-person evaluation and allergy testing.

Management of patients at risk of anaphylaxis after COVID 19 vaccination.

The success of a vaccination campaign depends on the possibility of guaranteeing not only a wide distribution of effective vaccines, but also on their safety and acceptance by the population. Vaccine safety questions should be answered by correct, unbiased and evidence-based reports, and by addressing all possible problems including allergic reactions. Despite the fact that many COVID-19 vaccines are free from the majority of potentially sensitizing components, an allergic reaction can occur even in the form of a severe, life-threatening anaphylaxis. The frequency of allergic reactions against COVID vaccine is greater than that observed for other vaccinations. National and international allergology societies have proposed specific guidelines for individuals at risk of anaphylaxis by vaccine. Vaccines, like all the pharmaceutical preparations, are submitted to great safety and efficacy valuations, however, even the greatest pre-licensure experimentations are insufficient to evaluate the vaccine's potential to provoke anaphylaxis. Therefore, post-market surveillance is essential to analyze, record and characterize all adverse events. To this purpose, specific algorithms should be used as a monitoring strategy of adverse events in patients undergoing vaccination against COVID 19.

COVID-19 vaccination: Recommendations for management of patients with allergy or immune-based diseases.

As South Africa continues to battle the second wave of SARS-CoV-2 infections, the imminent arrival of vaccines against COVID-19 offers hope. Vaccine roll-out has been accompanied by heightened media coverage that has created both excitement and anxiety, reporting on the shortened timeline of vaccine trials and approvals, as well as the recent series of anaphylaxis cases associated with the two approved mRNA COVID-19 vaccines. Patients with allergic and other immune-based diseases are subgroups especially concerned about vaccine safety and efficacy. This practice guideline offers broad recommendations for COVID-19 vaccination in various subgroups of allergic and immunebased disease, highlighting risk/benefit evaluation, and where and how routine vaccination should be altered.

Allergy to COVID-19 vaccines: A current update.

Adverse allergic reactions due to the administration of the vaccines developed for the protection of coronavirus disease 2019 (COVID-19) have been reported since the initiation of the vaccination campaigns. Current analyses provided by the Center for Disease Control and Prevention (CDC) and Food and Drug Administration (FDA) in the United States have estimated the rates of anaphylactic reactions in 2.5 and 11.1 per million of mRNA-1273 and BNT162b2 vaccines administered, respectively. Although rather low, such rates could have importance due to the uncommon fact that a large majority of the world population will be subjected to vaccination with the aforementioned vaccines in the following months and vaccination will most likely be necessary every season as for influenza vaccines. Health regulators have advised that any subject with a previous history of allergy to drugs or any component of the vaccines should not be vaccinated, however, certain misunderstanding exists since allergy to specific excipients in drugs and vaccines are in occasions misdiagnosed due to an absence of suspicion to specific excipients as allergenic triggers or due to inaccurate labeling or nomenclature. In this review, we provide an updated revision of the most current data regarding the anaphylactic reactions described for BNT162b2 vaccine, mRNA-1273 vaccine, and AZD1222 vaccine. We extensively describe the different excipients in the vaccines with the potential to elicit systemic allergic reactions such as polyethylene glycol (PEG), polysorbates, tromethamine/trometamol, and others and the possible immunological mechanisms involved.

Management of anaphylaxis due to COVID-19 vaccines in the elderly.

Older adults, especially men and/or those with diabetes, hypertension, and/or obesity, are prone to severe COVID-19. In some countries, older adults, particularly those residing in nursing homes, have been prioritized to receive COVID-19 vaccines due to high risk of death. In very rare instances, the COVID-19 vaccines can induce anaphylaxis, and the management of anaphylaxis in older people should be considered carefully. An ARIA-EAACI-EuGMS (Allergic Rhinitis and its Impact on Asthma, European Academy of Allergy and Clinical Immunology, and European Geriatric Medicine Society) Working Group has proposed some recommendations for older adults receiving the COVID-19 vaccines. Anaphylaxis to COVID-19 vaccines is extremely rare (from 1 per 100,000 to 5 per million injections). Symptoms are similar in younger and older adults but they tend to be more severe in the older patients. Adrenaline is the mainstay treatment and should be readily available. A flowchart is proposed to manage anaphylaxis in the older patients.

Allergische Reaktionen auf COVID-19-Impfungen ­ Was HNO-Ärzte wissen sollten ­ Teil 1: Immunologische Grundlagen von Allergien auf Impfstoffe, Immunmechanismen von allergischen und pseudoallergischen Reaktionen; Teil 2: Charakteristika der mRNA-Impfstoffe BNT162b2- und mRNA-1273 zur Prophylaxe von COVID-19 und assoziierte Immunphänomene; Teil 3: Praktische Aspekte der Prophylaxe, Diagnostik und Therapie von Allergien auf COVID-19-Impfstoffe.

Allergic reactions against mRNA COVID-19 vaccine are yet uncommon, but due to the high number of people who get this vaccination anaphylaxis will be seen. This is especially so in people who are sensitized to components of the vaccine. This article focuses on practical aspects of diagnostic possibilities, prevention, recognition and therapy of anaphylactic reactions. High-risk population, who should not get vaccinated; as well as people who need allergy diagnostics before vaccinations are discussed. In opinion of allergy experts patients with atopic allergies or venom allergies do not have a higher risk regarding anaphylaxic reaction due to COVID vaccination.