Immediate-type hypersensitivity to polyethylene glycols: a review

Anaphylaxis associated with the mRNA COVID-19 vaccines: Approach to allergy investigation

Reports about cases of anaphylaxis to mRNA vaccines have created anxiety in the community and could increase vaccine hesitancy in the population. There are no standardized protocols for allergy testing to mRNA vaccines. PEG is currently the only excipient in both vaccines with recognized allergenic potential. Allergy to PEG has been reported with increasing frequency over recent years, often in patients who had repeated systemic allergic reactions/anaphylaxis to several classes of drugs before diagnosis. Proposed protocols are based on current knowledge about potential mechanisms of anaphylaxis associated with the mRNA vaccines, and the assumption that polyethylene glycol (PEG) is the most likely culprit. Allergy testing to PEGs and mRNA vaccines is complex and carries the risk of anaphylaxis and should be conducted in a specialist drug allergy center. Appropriate PEG-free emergency medical treatment and supervision should be readily available.

ARIA-EAACI statement on severe allergic reactions to COVID-19 vaccines - An EAACI-ARIA Position Paper

Further to the approval of the Coronavirus disease 2019 (COVID-19) vaccine BNT162b2, several severe anaphylaxis cases occured within the first few days of public vaccination. An investigation is taking place to understand the cases and their triggers. The vaccine will be administered to a large number of individuals worldwide and there are raising concerns that severe adverse events might occur. With the current information, the European Academy of Allergy and Clinical Immunology (EAACI) states its position for the following preliminary recommendations that are to be revised as soon as more data emerge. To minimize the risk of severe allergic reactions in vaccinated individuals, it is urgently required to understand the specific nature of the reported severe allergic reactions, including the background medical history of the individuals affected and the mechanisms involved. To achieve this goal, all clinical and laboratory information should be collected and reported. Mild and moderate allergic patients should not be excluded from the vaccine as this could have a significant impact on reaching the goal of population immunity. Healthcare practitioners vaccinating against COVID-19 are required to be sufficiently prepared to recognize and treat anaphylaxis properly with the ability to administer adrenaline. Further to vaccine administration, a mandatory observation period of at least 15 minutes should be followed for all individuals. The current data have not shown any higher risk for patients suffering from allergic rhinitis or asthma, and this message should be clearly stated by physicians to enable our patients to trust the vaccine. More than 30% of the population suffers from allergic diseases and the benefit of the vaccination clearly outweighs the risk of severe COVID-19 development.

Covalently Crosslinked Hydrogels via Step-Growth Reactions: Crosslinking Chemistries, Polymers, and Clinical Impact

Hydrogels are an important class of biomaterials with the unique property of high-water content in a crosslinked polymer network. In particular, chemically crosslinked hydrogels have made a great clinical impact in past years because of their desirable mechanical properties and tunability of structural and chemical properties. Various polymers and step-growth crosslinking chemistries are harnessed for fabricating such covalently crosslinked hydrogels for translational research. However, selecting appropriate crosslinking chemistries and polymers for the intended clinical application is time-consuming and challenging. It requires the integration of polymer chemistry knowledge with thoughtful crosslinking reaction design. This task becomes even more challenging when other factors such as the biological mechanisms of the pathology, practical administration routes, and regulatory requirements add additional constraints. In this review, key features of crosslinking chemistries and polymers commonly used for preparing translatable hydrogels are outlined and their performance in biological systems is summarized. The examples of effective polymer/crosslinking chemistry combinations that have yielded clinically approved hydrogel products are specifically highlighted. These hydrogel design parameters in the context of the regulatory process and clinical translation barriers, providing a guideline for the rational selection of polymer/crosslinking chemistry combinations to construct hydrogels with high translational potential are further considered.

Optimizing investigation of suspected allergy to polyethylene glycols

BACKGROUND

Polyethylene glycols (PEGs) are polymers of varying molecular weight (MW) used widely as excipients in drugs and other products, including the mRNA vaccines against coronavirus disease 2019. Allergy to PEGs is rare. Skin testing and graded challenge carries a high risk of inducing systemic reactions.

OBJECTIVE

We evaluated skin prick test (SPT) results and in vitro reactivity over time to different MW PEGs and assessed cross-sensitization patterns in PEG allergy.

METHODS

Ten patients with previously diagnosed PEG allergy underwent SPT twice with PEGs 26 months apart. Lower MW (PEG 300, 3000, 6000) were tested, followed by PEG 20,000, in stepwise, increasing concentrations. Cross-sensitization to polysorbate 80 and poloxamer 407 was assessed. SPT was performed in 16 healthy controls. In vitro basophil histamine release (HR) test and passive sensitization HR test were performed in patients and controls.

RESULTS

Patients previously testing positive on SPT to PEG 3000 and/or 6000 also tested positive to PEG 20,000. Patients with a longer interval since diagnosis tested negative to lower MW PEGs and positive mainly to higher concentrations of PEG 20,000. Three patients developed systemic urticaria during SPT. Eight patients showed cross-sensitization to poloxamer 407 and 3 to polysorbate 80. All controls tested negative. In vitro tests showed limited usefulness.

CONCLUSIONS

Skin test reactivity to PEG can decrease over time, but titrated SPT with increasing concentrations of PEG 20,000 can be diagnostic when lower MW PEGs test negative. To avoid systemic reactions, stepwise SPT is mandatory.

SARS-CoV-2 Vaccination and Anaphylaxis: Recommendations of the French Allergy Community and the Montpellier World Health Organization Collaborating Center

Vaccines against COVID-19 (and its emerging variants) are an essential global intervention to control the current pandemic situation. Anaphylactic reactions have been reported after SARS-CoV2 RNA vaccines. Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction. This risk is estimated at 1/1,000,000 in the context of vaccine safety surveillance programs. The COVID-19 vaccination is rolling-out vastly in different courtiers and surveillance programs are key to monitor severe adverse reactions, such as anaphylaxis. Anaphylaxis due to vaccine is extremely rare and specific cases should receive individualized investigation and care. The here presented recommendations and follow-up from the French allergy community and the Montpellier WHO Collaborating Center in order to support the vaccination program and intends to support to healthcare professionals in their daily basis.

Pfizer-BioNTech COVID-19 Vaccine Tolerance in Allergic versus Non-Allergic Individuals

Individuals with a history of allergy are potentially at risk of suffering from adverse effects after COVID-19 vaccination. We sought to assess the tolerance towards the Pfizer-BioNTech vaccine in allergic patients. To address this issue, we used a questionnaire conducted on-line in a group of medical professionals who were vaccinated with the Pfizer-BioNTech vaccine. A total of 1808 respondents, out of whom 1707 received two doses of the vaccine, returned the questionnaire. Local reactions after injection were more frequent in allergic individuals after both doses (swelling p = 0.0003). Systemic adverse events (AE-SYS) occurred more often after the second than the first dose in both groups (allergic persons: 77.29% vs. 41.06%); vomiting and arthralgia occurred more often in allergic subjects (p = 0.0009). AE-SYS in allergic individuals lasted longer than in non-allergic ones after the first (p = 0.01) and the second dose (p = 0.0009). Allergic reactions after vaccination were reported more frequently in allergic subjects: after the first dose (p = 0.00001) and after the second dose (p = 0.001). Rhinitis was the most frequent symptom observed more often in allergic patients. No severe allergic reactions occurred during the full cycle of vaccination. Although the Pfizer-BioNTech vaccine is tolerated worse by allergic than non-allergic individuals, the occurring adverse symptoms are mild and do not preclude a successful completion of the vaccination cycle. The presence of symptoms suggestive of allergy does not constitute a condition of increased risk of developing clinically significant adverse events following Pfizer COVID-19 vaccination.

Primary care provider-reported prevalence of vaccine and polyethylene glycol allergy in Canada

Background

The coronavirus disease 2019 pandemic has highlighted the importance of accurate capture of vaccine, and vaccine component, allergy. There remains a gap in the prevalence literature from the perspective of direct primary care provider (PCP) reporting at a population level.

Objective

To determine the prevalence of PCP-documented vaccine and polyethylene glycol (PEG) allergy using electronic medical record data from the Canadian Primary Care Sentinel Surveillance Network.

Methods

Retrospective cohort study using the Canadian Primary Care Sentinel Surveillance Network repository. Machine learning algorithms were applied to evaluate for vaccine allergy documentation, and Anatomic Therapeutic Chemical codes were used for PEG allergy or allergy to common injectable medications containing PEG (CIMCP).

Results

The prevalence of PCP-documented vaccine allergy in Canada was 0.037% (395/1,055,677) and of PEG allergy was 0.0009% (10/1,055,677). In total, 0.01% of patients had a documented allergy to either PEG or CIMCP (135/1,055,677). None of the patients with PEG allergy had a documented allergy to a CIMCP. Patients with vaccine allergy and PEG allergy were significantly more likely to have other atopic comorbidities, including asthma (P < .001 for both), eczema (P < .001 and P = .001, respectively), rhinitis (P = .002 and P < .001, respectively), and food allergy (P < .001 for both). Significantly higher rates of depression (P < .001 and P < .001, respectively) and anxiety (P = .003 and P < .001, respectively) were found in those with vaccine allergy, or PEG allergy, than those without vaccine allergy or PEG allergy.

Conclusion

This is the first study to estimate the prevalence of vaccine and PEG allergy in a national cohort that uses PCP documentation, revealing a low reported rate of vaccine allergy and PEG allergy.

Praktischer Umgang mit allergischen Reaktionen auf COVID-19-Impfstoffe

Hintergrund: Zur vorbeugenden Behandlung von COVID-19 (Coronaviruserkrankung 2019) wurden in einer beispiellosen weltweiten Forschungsanstrengung Sicherheit und Wirksamkeit neuer Impfstoffplattformen studiert, die noch nie zuvor am Menschen eingesetzt wurden. Weniger als ein Jahr nach der Entdeckung der SARS-CoV-2-Virussequenz (SARS-CoV-2, "severe acute respiratory syndrome coronavirus type 2") wurden diese in zahlreichen Ländern für den Einsatz zugelassen und es wurde mit Massenimpfungen begonnen. Die bislang in der Europäischen Union (EU) zugelassenen mRNA-Impfstoffe (mRNA, "messenger"-RNA) gegen SARS-CoV-2 BNT162b2 und mRNA-1273 basieren auf einer ähnlichen lipidbasierten Nanopartikelträgertechnologie; die Lipidkomponenten unterscheiden sich jedoch. Schwere allergische Reaktionen und Anaphylaxien nach COVID-19-Impfungen sind sehr seltene unerwünschte Nebenwirkungen, die aber aufgrund potenziell letaler Ausgänge viel Aufmerksamkeit erhalten und ein hohes Maß an Verunsicherung ausgelöst haben.

Methoden: Das aktuelle Wissen zu anaphylaktischen Reaktionen auf Impfstoffe und speziell zu den derzeit neuen mRNA-COVID-19-Impfstoffen wurde zusammengestellt mittels einer Literaturanalyse durch Recherchen in Medline, Pubmed sowie den nationalen und internationalen Studien- und Leitlinienregistern, der Cochrane Library und dem Internet unter besonderer Berücksichtigung offizieller Webseiten der World Health Oranization (WHO), der Centers for Disease Control and Prevention (CDC), der European Medicines Agency (EMA), des Robert-Koch-Instituts (RKI) und des Paul-Ehrlich-Instituts (PEI).

Ergebnisse: Basierend auf der internationalen Literatur und bisheriger Erfahrungen zu schweren allergischen Reaktionen im Kontext der COVID-19-Impfungen werden von einem Expertengremium Empfehlungen für Prophylaxe, Diagnostik und Therapie dieser allergischen Reaktionen gegeben.

Schlussfolgerung: Vor einer COVID-19-Impfung mit den derzeit zugelassenen Impfstoffen sind Allergietests für die allermeisten Allergiker nicht notwendig. Bei allergischer/anaphylaktischer Reaktion auf den verabreichten COVID-19-Impfstoff wird eine allergologische Abklärung empfohlen, wie auch für eine kleine potenzielle Risikopopulation vor der ersten Impfung. Die Evaluierung und Zulassung von Testverfahren sollten hierfür erfolgen.

Zitierweise: Klimek L, Bergmann K-C, Brehler R, Pfützner W, Zuberbier T, Hartmann K, Jakob T, Novak N, Ring J, Merk H; Hamelmann E, Ankermann T, Schmidt S, Untersmayr E, Hötzenecker W, Jensen-Jarolim E, Brockow K, Mahler V, Worm M. Practical Handling of Allergic Reactions to COVID-19 vaccines. A Position Paper from German and Austrian Allergy Societies AeDA, DGAKI, GPA and ÖGAI. Allergo J Int 2021;30:79-95

https: //doi.org/10.1007/s40629-021-00165-7

Successful SARS-CoV-2 vaccine allergy risk-management: The experience of a large Italian University Hospital

BACKGROUND

Novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccines have been approved recently, and public concern regarding the risk of anaphylactic reactions arose after a few cases during the first days of mass vaccination. Polyethylene glycol (PEG) has been suggested as the most probable culprit agent for allergic reactions.

OBJECTIVE

We describe the allergy work-up protocol implemented for the vaccination campaign in our Center, aiming to allow the greatest number of people to be vaccinated safely.

METHODS

The protocol included the self-report of a history of suspected drug or vaccine allergies, and subsequent teleconsultation and allergometric tests for PEG and Polysorbate 80 (PS80). A desensitizing protocol of vaccine administration was applied to patients sensitized only to PS80, and to those with a suspect allergic reaction after the first vaccine dose.

RESULTS

10.2% (414 out of 4042) of the entire vaccine population have been screened: only one patient resulted allergic to PEG and therefore excluded from the vaccination. Another patient was sensitized to PS80 only and safely vaccinated applying the desensitizing protocol. Seven subjects without a previous history of allergic disease experienced suspect hypersensitivity reactions to the first administered dose: one of them resulted allergic to PEG and was excluded from the second dose, while the others safely completed the vaccination with the desensitizing protocol.

CONCLUSION

A careful allergological risk-assessment protocol significantly reduces the number of patients who would have avoided SARS-CoV-2 vaccination for their allergies and to effectively identify and manage those rare patients with sensitization to PEGs and/or PS80.

Cutaneous adverse effects of the available COVID-19 vaccines

Vaccination has played a crucial role in the improvement of global health. Some of the world's deadliest diseases, like smallpox and rinderpest, have been eradicated with the help of vaccines, and many others have been restrained. The appearance of the strain of coronavirus disease 2019 (COVID-19) severe acute respiratory syndrome coronavirus 2 and its impact on global health have made the development of effective and safe vaccines crucial for this new lethal disease. So far, there are three main types of COVID-19 vaccines in use around the world: messenger RNA-based vaccines, adenoviral vector vaccines, and inactivated whole-virus vaccines. Some of them have passed through phase 3 of safety and efficacy trials and are widely used for prophylaxis of COVID-19 infection. A plethora of cutaneous adverse events have been reported, most of them mild or moderate injection-site reactions. Some rare delayed inflammatory reactions such as "COVID arm" have also been reported, posing questions on their pathophysiology and clinical importance. Some rare serious adverse events, such as vaccine-induced prothrombotic immune thrombocytopenia and anaphylaxis, have been described raising great concerns on the safety of some widely spread vaccines. More data need to be collected with further and more detailed analysis. The overall risk of such severe adverse reactions remains extremely low, and the benefits of the existing vaccines in combating the widespread threat of COVID-19 continue to outweigh the risk of their side effects.

Practical handling of allergic reactions to COVID-19 vaccines: A position paper from German and Austrian Allergy Societies AeDA, DGAKI, GPA and ÖGAI

BACKGROUND

For the preventive treatment of the 2019 coronavirus disease (COVID-19) an unprecedented global research effort studied the safety and efficacy of new vaccine platforms that have not been previously used in humans. Less than one year after the discovery of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral sequence, these vaccines were approved for use in the European Union (EU) as well as in numerous other countries and mass vaccination efforts began. The so far in the EU approved mRNA vaccines BNT162b2 and mRNA-1273 are based on similar lipid-based nanoparticle carrier technologies; however, the lipid components differ. Severe allergic reactions and anaphylaxis after COVID-19 vaccination are very rare adverse events but have drawn attention due to potentially lethal outcomes and have triggered a high degree of uncertainty.

METHODS

Current knowledge on anaphylactic reactions to vaccines and specifically the new mRNA COVID-19 vaccines was compiled using a literature search in Medline, PubMed, as well as the national and international study and guideline registries, the Cochrane Library, and the Internet, with special reference to official websites of the World Health Organization (WHO), US Centers for Disease Control and Prevention (CDC), Robert Koch Institute (RKI), and Paul Ehrlich Institute (PEI).

RESULTS

Based on the international literature and previous experience, recommendations for prophylaxis, diagnosis and therapy of these allergic reactions are given by a panel of experts.

CONCLUSION

Allergy testing is not necessary for the vast majority of allergic patients prior to COVID-19 vaccination with currently licensed vaccines. In case of allergic/anaphylactic reactions after vaccination, allergy workup is recommended, as it is for a small potential risk population prior to the first vaccination. Evaluation and approval of diagnostic tests should be done for this purpose.

Prolonged Anaphylaxis to Pfizer Coronavirus Disease 2019 Vaccine: A Case Report and Mechanism of Action

Background:

In response to the devastating effects of the coronavirus disease 2019 pandemic, several vaccine prototypes have been developed, with the Pfizer/BioNTech (BNT162b2) platform being the first to receive emergency use authorization. Although taken to market on an unprecedented timeline, the safety profile of the drug during clinical trials was shown to be favorable. Shortly after release, reports from the Centers for Disease Control and Prevention demonstrated a higher-than-average rate of anaphylaxis to the vaccine that has been the cause for concern for safety officials and the general public alike. Here, we present a unique case of protracted anaphylaxis in a recipient of the BNT162b2.

Case Summary:

The patient is a 55-year-old female with a history of multiple allergic reactions who presented with respiratory distress and hives after receiving the first dose of the BNT162b2, despite premedication with IV steroids and diphenhydramine. The refractory nature of her reaction was demonstrated by edema of her tongue (visualized on nasolaryngoscopy), requiring an epinephrine infusion for nearly 3 days. She was discharged from the hospital with instructions not to receive the second dose of the vaccine.

Conclusion:

Although the exact etiology of anaphylaxis secondary to this messenger RNA-based vaccine is not completely clear, our literature search and review of the patient’s course support either polyethylene glycol versus other excipient-related allergy as a possible cause. Based on the protracted nature to our patient’s anaphylaxis, critical care management for patients with a true anaphylactic reaction to BNT162b2 may require monitoring for an extended period of time.

Mechanisms of human drug-induced anaphylaxis

Drug-induced anaphylaxis is a hyperacute reaction affecting multiple organs that can be of fatal consequence. Its incidence is increasing, consistent with a global increased sensitization to various allergens and drugs in the population. Few risk factors and mechanisms have been identified from human studies due to the rarity of anaphylactic events and their unpredictability. This systemic reaction is caused by the rapid release of a large range of functionally diverse mediators, including histamine and platelet-activating factor as the main drivers identified. Mechanisms defined from models of experimental anaphylaxis identify drug-specific antibodies of the IgE and IgG class that link the drug to antibody receptors on multiple cell types, causing their activation and mediator release. In the case of drugs with peculiar chemical structures, antibodies may not be necessary because drug-binding receptors, such as Mas-related G protein-coupled receptor member X2, have been identified. This review describes the complex reaction leading to drug-induced anaphylaxis that can involve various antibody classes, various cell types-including mast cells, neutrophils, platelets, basophils, macrophages, and monocytes-and their mediators and receptors that, importantly, can be activated alone or in association to participate in the severity of the reaction.

mRNA Vaccines to Prevent COVID-19 Disease and Reported Allergic Reactions: Current Evidence and Suggested Approach

The U.S. Food and Drug Administration (FDA) has recently issued an Emergency Use Authorization (EUA) for 2 highly effective coronavirus disease 2019 (COVID-19) vaccines from Pfizer-BioNTech and Moderna. This has brought hope to millions of Americans in the midst of an ongoing global pandemic. The FDA EUA guidance for both vaccines is to not administer the vaccine to individuals with a known history of a severe allergic reaction (eg, anaphylaxis) to any component of the COVID-19 vaccine. The Centers for Disease Control and Prevention (CDC) additionally advises individuals with a history of an immediate allergic reaction to a vaccine or injectable or any history of anaphylaxis be observed for 30 minutes after COVID-19 vaccination. All other individuals should be observed for 15 minutes after COVID-19 vaccination. Staff at vaccine clinics must be able to identify and manage anaphylaxis. Post-FDA EUA, despite very strong safety signals in both phase 3 trials, reports of possible allergic reactions have raised public concern. To provide reassurance and support during widespread global vaccination, allergists must offer clear guidance to individuals based on the best information available, but also in accordance with the broader recommendations of regulatory agencies. This review summarizes vaccine allergy epidemiology and proposes drug and vaccine allergy expert opinion informed risk stratification for Allergy specialist use in conjunction with guidance of public health and regulatory authorities. The risk stratification schema guide care for (1) individuals with different allergy histories to safely receive their first mRNA COVID-19 vaccine and (2) individuals who develop a reaction to their first dose of mRNA COVID-19 vaccine.

Polyglycerol for Half-Life Extension of Proteins-Alternative to PEGylation?

Since several decades, PEGylation is known to be the clinical standard to enhance pharmacokinetics of biotherapeutics. In this study, we introduce polyglycerol (PG) of different lengths and architectures (linear and hyperbranched) as an alternative polymer platform to poly(ethylene glycol) (PEG) for half-life extension (HLE). We designed site-selective N-terminally modified PG-protein conjugates of the therapeutic protein anakinra (IL-1ra, Kineret) and compared them systematically with PEG analogues of similar molecular weights. Linear PG and PEG conjugates showed comparable hydrodynamic sizes and retained their secondary structure, whereas binding affinity to IL-1 receptor 1 decreased with increasing polymer length, yet remained in the low nanomolar range for all conjugates. The terminal half-life of a 40 kDa linear PG-modified anakinra was extended 4-fold compared to the unmodified protein, close to its PEG analogue. Our results demonstrate similar performances of PEG- and PG-anakinra conjugates and therefore highlight the outstanding potential of polyglycerol as a PEG alternative for half-life extension of biotherapeutics.

Schwere allergische Reaktionen nach COVID-19-Impfung mit dem Impfstoff von Pfizer/BioNTech in Großbritannien und USA

Zwei Mitarbeiter des National Health Service (NHS) in England entwickelten nach der Verabreichung des BNT162b2-Impfstoffs von BionNTech gegen COVID-19 schwere allergische Reaktionen. Die britische Fachinformation für den BNT162b2-Impfstoff enthält bereits Hinweise auf eine Kontraindikation zur Anwendung bei Personen, die allergisch auf den Impfstoff oder einen seiner Bestandteile reagiert haben. Als Vorsichtsmaßnahme hat die englische Regulationsbehörde für Arzneimittel und Gesundheitsprodukte (MHRA) eine vorläufige Anleitung herausgegeben, "Patienten mit schweren Allergien" grundsätzlich nicht zu impfen. Allergische Reaktionen auf Impfstoffe sind sehr selten, aber Impfstoffkomponenten verursachen bekanntermaßen allergische Reaktionen. BNT162b2 ist ein Impfstoff, der auf einer in Lipidnanopartikel eingebetteten mRNA basiert und mit weiteren Substanzen angereichert wird, um den Transport in die Zellen zu ermöglichen. In der zentralen klinischen Phase-III-Studie wurde der BNT162b2-Impfstoff im Allgemeinen gut vertragen. Impfstoffe gelten als eine der wirksamsten Maßnahmen im Bereich der öffentlichen Gesundheit. Schwere allergische Reaktionen auf Impfstoffe sind selten, können jedoch lebensbedrohlich sein. Es ist ratsam, die Impfteams auf diese Gefahr aufmerksam zu machen und angemessene Vorsichtsmaßnahmen zu treffen, während mehr Erfahrungen mit dem neuen Impfstoff gesammelt werden.

COVID-19 vaccine testing & administration guidance for allergists/immunologists from the Canadian Society of Allergy and Clinical Immunology (CSACI)

BACKGROUND

Safe and effective vaccines provide the first hope for mitigating the devastating health and economic impacts resulting from coronavirus disease 2019 (COVID-19) and related public health orders. Recent case reports of reactions to COVID-19 vaccines have raised questions about their safety for use in individuals with allergies and those who are immunocompromised. In this document, we aim to address these concerns and provide guidance for allergists/immunologists.

METHODS

Scoping review of the literature regarding COVID-19 vaccination, adverse or allergic reactions, and immunocompromise from PubMed over the term of December 2020 to present date. We filtered our search with the terms "human" and "English" and limited the search to the relevant subject age range with the term "adult." Reports resulting from these searches and relevant references cited in those reports were reviewed and cited on the basis of their relevance.

RESULTS

Assessment by an allergist is warranted in any individual with a suspected allergy to a COVID-19 vaccine or any of its components. Assessment by an allergist is NOT required for individuals with a history of unrelated allergies, including to allergies to foods, drugs, insect venom or environmental allergens. COVID-19 vaccines should be offered to immunocompromised patients if the benefit is deemed to outweigh any potential risks of vaccination.

INTERPRETATION

This review provides the first Canadian guidance regarding assessment of an adolescent and adult with a suspected allergy to one of the COVID-19 vaccines currently available, or any of their known allergenic components, and for patients who are immunocompromised who require vaccination for COVID-19. As information is updated this guidance will be updated accordingly.

A Cost-Effectiveness Evaluation of Hospitalizations, Fatalities, and Economic Outcomes Associated with Universal Versus Anaphylaxis Risk-Stratified COVID-19 Vaccination Strategies

BACKGROUND

Vaccine-associated anaphylaxis is a rare event (1.34 events/million doses; 0.00017% occurrence over 26 years). Several reports of allergic reactions concerning for anaphylaxis have been reported early into the Pfizer-BioNTech and Moderna coronavirus disease 2019 (COVID-19) vaccine campaign in the United States, Canada, and the United Kingdom.

OBJECTIVE

To perform a cost-effectiveness analysis characterizing the risks of COVID-19 versus vaccine anaphylaxis, comparing universal COVID-19 vaccination versus risk-stratified vaccination approaches.

METHODS

Cohort analysis models were created to evaluate the cost-effectiveness of universal vaccination versus risk-stratified vaccination (eg, contraindicated in persons with a history of any previous episode of anaphylaxis) with a threshold for cost-effective care at $10,000,000 per death prevented. In the base case, risk of anaphylaxis was estimated at 0.1%, with case-fatality estimated at 0.3%.

RESULTS

On a population level (n = 300,000,000 simulated persons), universal vaccination was associated with a cost-savings of $503,596,316 and saved 7,607 lives, but the cost-savings was sensitive to increasing rates of vaccine-associated anaphylaxis. The universal strategy dominated at higher rates of COVID-19 infection and low rates of vaccine-associated anaphylaxis in both the health care and societal perspectives. When the risk of vaccine-associated anaphylaxis exceeded 0.8%, the risk-stratified approach to vaccination was the most cost-effective strategy. There was also an interaction between anaphylaxis risk and anaphylaxis fatality, with a risk-stratified approach becoming cost-effective as each risk increased concurrently. Stratified observation time by anaphylaxis history (15 minutes vs 30 minutes) was not cost-effective until a 1% anaphylaxis case-fatality was assumed and risk of vaccine anaphylaxis exceeded 6%.

CONCLUSIONS

This study demonstrates that unless vaccine anaphylaxis rates exceed 0.8%, a universal vaccination approach dominates a risk-stratified approach where persons with any history of anaphylaxis would be contraindicated from vaccination, with lower cost and superior health outcomes.

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.

[Allergic reactions to COVID-19 vaccines: evidence and practice-oriented approach]

Less than a year after the first detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), vaccines have been approved for routine use in numerous countries and have already been used in mass vaccination programs. Vaccines include the mRNA BNT162b2 and mRNA 1273. Allergic reactions and anaphylaxis account for a substantial proportion of the adverse reactions to these vaccines observed to date, but overall they are rare. The incidence of anaphylaxis in the context of SARS-CoV‑2 vaccination with the mRNA vaccines appears to be approximately 10-fold higher than with previous vaccines, at approximately 1 per 100,000 vaccine injections. One focus of the present article is a systematic review of the components of mRNA vaccines against " coronavirus disease 2019 " (COVID-19). Differences from established vaccines are addressed and the allergic potential of liposomes, polyethylene glycol, tromethamine/trometamol, and mRNA are discussed. Another focus is on the clinical presentation and course of allergic reactions to the COVID-19 vaccines. This is followed by a discussion of the therapeutic approach to anaphylactic reactions, as well as the drugs and medical supplies required to treat them. It is important to note that any vaccinee may be affected by anaphylaxis, regardless of whether or not allergic diseases are already known. Therefore, every vaccination site and every vaccinator must be prepared to recognize and treat severe allergic reactions.

PEG That Reaction: A Case Series of Allergy to Polyethylene Glycol

Polyethylene glycol (PEG), also known as macrogol, is an excipient in numerous medications, health care products, cosmetics, and foods. It acts as an inert bulking, or stabilizing, agent. Despite its ubiquity, including in 2 of the newly launched vaccines against SARS‐CoV‐2, awareness of PEG allergy remains low. We present 6 cases of acute hypersensitivity to PEG. Accurate diagnoses in these cases posed a challenge, and although the triggering agents differed, PEG was demonstrated as the common culprit. All cases were female, with a mean age of 36.4 years. Four patients were originally suspected to have nonsteroid anti‐inflammatory drug allergy, and 2 had a history of chronic spontaneous urticaria and angioedema. Biphasic allergic reactions featured prominently in this case series. Diagnosis relies on a high index of suspicion leading to a focused clinical history, supported by skin tests with PEG solutions to demonstrate sensitization. This case series highlights important clinical features of this rare, potentially serious, and increasingly recognized excipient allergy.

Severe allergic reactions after COVID-19 vaccination with the Pfizer/BioNTech vaccine in Great Britain and USA: Position statement of the German Allergy Societies: Medical Association of German Allergologists (AeDA), German Society for Allergology and Clinical Immunology (DGAKI) and Society for Pediatric Allergology and Environmental Medicine (GPA)

Two employees of the National Health Service (NHS) in England developed severe allergic reactions following administration of BNT162b2 vaccine against COVID-19 (coronavirus disease 2019). The British SmPC for the BNT162b2 vaccine already includes reference to a contraindication for use in individuals who have had an allergic reaction to the vaccine or any of its components. As a precautionary measure, the Medicines and Healthcare products Regulatory Agency (MHRA) has issued interim guidance to the NHS not to vaccinate in principle in "patients with severe allergies". Allergic reactions to vaccines are very rare, but vaccine components are known to cause allergic reactions. BNT162b2 is a vaccine based on an mRNA embedded in lipid nanoparticles and blended with other substances to enable its transport into the cells. In the pivotal phase III clinical trial, the BNT162b2 vaccine was generally well tolerated, but this large clinical trial, used to support vaccine approval by the MHRA and US Food and Drug Administration, excluded individuals with a "history of a severe adverse reaction related to the vaccine and/or a severe allergic reaction (e.g., anaphylaxis) to a component of the study medication". Vaccines are recognized as one of the most effective public health interventions. This repeated administration of a foreign protein (antigen) necessitates a careful allergological history before each application and diagnostic clarification and a risk-benefit assessment before each injection. Severe allergic reactions to vaccines are rare but can be life-threatening, and it is prudent to raise awareness of this hazard among vaccination teams and to take adequate precautions while more experience is gained with this new vaccine.

COVID-19 vaccine-associated anaphylaxis: A statement of the World Allergy Organization Anaphylaxis Committee

Vaccines against COVID-19 (and its emerging variants) are an essential global intervention to control the current pandemic situation. Vaccines often cause adverse events; however, the vast majority of adverse events following immunization (AEFI) are a consequence of the vaccine stimulating a protective immune response, and not allergic in etiology. Anaphylaxis as an AEFI is uncommon, occurring at a rate of less than 1 per million doses for most vaccines. However, within the first days of initiating mass vaccination with the Pfizer-BioNTech COVID-19 vaccine BNT162b2, there were reports of anaphylaxis from the United Kingdom and United States. More recent data imply an incidence of anaphylaxis closer to 1:200,000 doses with respect to the Pfizer-BioNTech vaccine. In this position paper, we discuss the background to reactions to the current COVID-19 vaccines and relevant steps to mitigate against the risk of anaphylaxis as an AEFI. We propose a global surveillance strategy led by allergists in order to understand the potential risk and generate data to inform evidence-based guidance, and thus provide reassurance to public health bodies and members of the public.

Practical recommendations for the allergological risk assessment of the COVID-19 vaccination - a harmonized statement of allergy centers in Germany

Severe allergic reactions to vaccines are very rare. Single severe reactions have occurred worldwide after vaccination with the new mRNA-based COVID-19 vaccines. PEG2000 is discussed as a possible trigger. We provide guidance on risk assessment regarding COVID-19 vaccination in patients with allergic diseases and suggest a standardized, resource-oriented diagnostic and therapeutic procedure. Reports of severe allergic reactions in the context of COVID-19 vaccination can be made via www.anaphylaxie.net using an online questionnaire.

Clinical manifestations and impact on daily life of allergy to polyethylene glycol (PEG) in ten patients

BACKGROUND

Polyethylene glycols (PEGs) are widely used as excipients in drugs, cosmetics and household products. Immediate-type allergy to PEGs including anaphylaxis is rare. The recent introduction of the mRNA-based COVID-19 vaccines has led to an increased focus on PEG as a possible culprit of allergic reactions to the vaccines. A low awareness of the allergenic potential of PEG among consumers, manufacturers and doctors leads to under-diagnosis and under-reporting of allergy to PEGs, putting patients at risk of repeated severe reactions.

OBJECTIVES

To investigate clinical manifestations, time to diagnosis and impact of a PEG allergy diagnosis on the daily life of patients diagnosed with allergy to PEG from 2010 to 2019.

METHOD

Ten patients diagnosed with allergy to PEG were included. Detailed clinical history was obtained, and allergy investigations had been performed at the time of diagnosis. All patients were contacted and asked to retrospectively complete a questionnaire about causes and impact on daily life of an allergy to PEG, scored on a likert scale (0-10) before and after diagnosis.

RESULTS

Eight patients had experienced at least one anaphylactic reaction requiring adrenaline treatment. Anaphylaxis was primarily caused by antibiotic/analgesic tablets, depot-steroids, antacids and laxatives. Seven patients reported repeated reactions before diagnosis (median 3, range 2-6). Median time from first reaction to diagnosis was 20 months (range 2-120). None of the patients experienced severe allergic reactions after the diagnosis. Median likert score of the impact on daily life before diagnosis was 7 compared with 4 after diagnosis.

CONCLUSION AND CLINICAL RELEVANCE

The clinical manifestations of PEG allergy are often dramatic. Improved awareness about the clinical presentation and common culprits, clear product labelling and a standardized nomenclature is needed to ensure the timely diagnosis of PEG allergy to prevent repeated anaphylactic reactions with severe impact on patients' lives.

COVID-19 Vaccine-associated Anaphylaxis and Allergic Reactions: Consensus Statements of the KAAACI Urticaria/Angioedema/Anaphylaxis Working Group

In the era of novel coronavirus epidemics, vaccines against coronavirus disease 2019 (COVID-19) have been recognized as the most effective public health interventions to control the pandemic. An adverse event following immunization (AEFI) is defined as any untoward occurrence following immunization, and the majority of AEFIs are caused by protective immune responses stimulated by vaccines. Most of the reported AEFIs are not serious, and many are not immunologically mediated or even reproducible on re-exposure. However, uncommon severe allergic adverse reactions, such as anaphylaxis or other allergic reactions, can occur after vaccinations. Confirmed allergic reactions to vaccines may be caused by residual non-human protein, preservatives, or stabilizers in the vaccine formulation (also known as excipients). There are 2 main potential allergenic/immunogenic excipients in COVID-19 vaccines, polyethylene glycol (PEG) and polysorbate 80. PEG, also known as macrogol, is an ingredient in various laxatives and injectable formulations, such as depot steroids. Polysorbate 80 is present in various medical products, creams, ointments, lotions, and medication tablets. Contraindications to the administration of COVID-19 vaccines include a previous history of severe allergic reactions to the first dose of COVID-19 vaccine or proven hypersensitivity to a vaccine component, such as PEG or polysorbate 80. Anaphylaxis or other allergic reactions following immunization can cause fear and loss of confidence in the safety of vaccines among the public. A better understanding of these events is thought to help alleviate concerns about the current COVID-19 vaccines and provide reassurance to the general population by analyzing the exact incidence of anaphylaxis and potential risk factors. COVID-19 vaccine-associated anaphylaxis could be prevented and managed by risk stratification based on our local and global experience.

Biomedical nanomaterials for immunological applications: ongoing research and clinical trials

Research efforts on nanomaterial-based therapies for the treatment of autoimmune diseases and cancer have spiked and have made rapid progress over the past years. Nanomedicine has been shown to contribute significantly to overcome current therapeutic limitations, exhibiting advantages compared to conventional therapeutics, such as sustained drug release, delayed drug degradation and site-specific drug delivery. Multiple nanodrugs have reached the clinic, but translation is often hampered by either low targeting efficiency or undesired side effects. Nanomaterials, and especially inorganic nanoparticles, have gained criticism due to their potential toxic effects, including immunological alterations. However, many strategies have been attempted to improve the therapeutic efficacy of nanoparticles and exploit their unique properties for the treatment of inflammation and associated diseases. In this review, we elaborate on the immunomodulatory effects of nanomaterials, with a strong focus on the underlying mechanisms that lead to these specific immune responses. Nanomaterials to be discussed include inorganic nanoparticles such as gold, silica and silver, as well as organic nanomaterials such as polymer-, dendrimer-, liposomal- and protein-based nanoparticles. Furthermore, various approaches for tuning nanomaterials in order to enhance their efficacy and attenuate their immune stimulation or suppression, with respect to the therapeutic application, are described. Additionally, we illustrate how the acquired insights have been used to design immunotherapeutic strategies for a variety of diseases. The potential of nanomedicine-based therapeutic strategies in immunotherapy is further illustrated by an up to date overview of current clinical trials. Finally, recent efforts into enhancing immunogenic cell death through the use of nanoparticles are discussed.

[Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis]

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.