International Consensus (ICON): allergic reactions to vaccines

A 13.2 mg epinephrine intranasal spray demonstrates comparable pharmacokinetics, pharmacodynamics, and safety to a 0.3 mg epinephrine autoinjector

Background

Recent acute anaphylaxis guideline updates have identified remaining unmet needs based on currently available therapeutic options as a critical focus.

Objective

We compared the pharmacokinetic, pharmacodynamic, safety, and tolerability profiles of intranasal epinephrine with intramuscular epinephrine administered by autoinjector and manual syringe.

Methods

An open-label, 3-period crossover study was conducted in 116 healthy adult volunteers to assess the bioavailability of a single 13.2 mg intranasal dose of epinephrine compared to a 0.3 mg intramuscular autoinjector and a 0.5 mg manual syringe. Patients with epinephrine concentrations of 50, 100, and 200 pg/mL at 10, 20, 30, and 60 minutes after dosing were also evaluated.

Results

Pharmacokinetic parameters for the 13.2 mg intranasal dose exceeded those of the 0.3 mg autoinjector with a rapid and higher maximum observed concentration (intranasal, 429.4 pg/mL; autoinjector, 328.6 pg/mL) and greater systemic exposure (AUC0-360; intranasal, 39,060 pg∙min/mL; autoinjector, 17,440 pg∙min/mL). Similar results were observed compared to the 0.5 mg manual syringe. Pharmacokinetic parameters for opposite-nostril and same-nostril dosing were higher than both intramuscular doses, except time to reach maximum observed concentration, which was bracketed between the 2 intramuscular doses (intranasal opposite and same nostril, 20 minutes; autoinjector, 14.9 minutes; manual syringe, 45 minutes). Similar effects on blood pressure and heart rate were observed for intranasal and autoinjector administration. Intranasal epinephrine was safe and well tolerated. No serious or unexpected adverse events were reported, confirming results from earlier clinical studies.

Conclusions

Bidose epinephrine spray addresses the unmet medical and patient needs for a needle-free, convenient, and effective dose-delivery system for self-administration of epinephrine that is as good as or better than the 0.3 mg autoinjector.

Recent findings on drug hypersensitivity in children

Drug hypersensitivity reactions (DHR) in children have a significant impact on clinical practice and public health. Both under-diagnosis (due to under-reporting) and over-diagnosis (due to the overuse of the term "allergy") are potential issues. The aim of this narrative review is to describe the most recent findings of DHR in children/adolescents and gaps regarding epidemiology, antibiotic allergy, antiepileptic hypersensitivity, vaccine allergy, and severe cutaneous adverse reactions (SCAR) in this age group.

An Update in COVID-19 Vaccine Reactions in 2023: Progress and Understanding

It has been 3 years since the coronavirus disease 2019 (COVID-19) pandemic was initially declared, and 2 years have passed since the first COVID-19 vaccines were introduced. Since then, 13.2 billion COVID-19 vaccine doses have been administered worldwide, largely with multiple doses of messenger RNA vaccines. Although mild local and systemic adverse effects after COVID-19 vaccination are common, serious adverse effects following immunization are rare, particularly when compared with the large number of vaccine doses administered. Immediate and delayed reactions are relatively common and present similarly to allergic and hypersensitivity reactions. Despite this, reactions generally do not commonly recur, cause sequelae, or contraindicate revaccination. In this Clinical Management Review, we provide an updated perspective of COVID-19 vaccine reactions, their spectrum and epidemiology, and recommended approaches to evaluation and management.

Evaluating immune responses to pneumococcal vaccines

Streptococcus pneumoniae (pneumococcus) is a significant cause of bacterial infections ranging from mild infections affecting the respiratory tract such as otitis media and sinusitis to severe diseases including bacteremia, pneumonia, and invasive pneumococcal disease (IPD) (eg, meningitis, septic arthritis, and endocarditis). Pneumococcal vaccines were first developed in the 1970s as capsular pneumococcal polysaccharide vaccines, which were T-cell independent and hence lacked immunologic memory. Subsequently in the year 2000, pneumococcal conjugate vaccines (PCV) conjugated to a protein to increase immunogenicity were developed and made commercially available. The increasing number of pneumococcal serotypes identified and the expanding pipeline of PCV vaccines with improved immunogenicity have significantly reduced the morbidity and mortality associated with IPD in high-risk patients. Pneumococcal vaccines also play an important role in the diagnosis and immunophenotyping of children and adults with inborn errors of immunity (IEI) given the increasing diversity/heterogeneity of IEI presenting with primary and/or specific antibody deficiency. Other than the quantitation of serotype levels in routine clinical care, other measurements of immune response including the functional activity of antibodies, antibody avidity, cell-mediated immunity, and immunological memory remain limited to clinical trials during vaccine development.

Evaluation of Children with Cow's Milk Allergy Who Received Measles or Measles, Mumps, and Rubella Vaccines Containing Alpha-Lactalbumin

Objective: Cases of cow's milk allergy (CMA) who reacted to measles or measles, mumps, and rubella (MMR) vaccines containing alpha-lactalbumin have been reported. The purpose of this study was to assess patients with CMA who received measles or MMR vaccines containing alpha-lactalbumin, as well as the characteristics of those who developed reactions to these vaccines. Study Design: Patients followed up in the allergy clinic for CMA and who received measles or MMR vaccines containing alpha-lactalbumin at 9 or 12 months of age were included in the study, and their characteristics were analyzed retrospectively from the hospital registry system. Results: Forty-nine patients were included in the study. Six patients received the measles vaccine, whereas 43 patients received the MMR vaccine containing alpha-lactalbumin. Vaccine skin tests were performed on these 6 patients. One patient had a positive intradermal test, so an alternative vaccine not containing alpha-lactalbumin was administered. The other 5 patients were vaccinated, and no reaction was observed. Anaphylaxis was observed in 3 of 43 patients who received the MMR vaccine containing alpha-lactalbumin. In all of these patients, the first reaction to dairy products was anaphylaxis. In 2 of those patients, cow's milk-specific IgE (spIgE) levels were >100 kU/L, and alpha-lactalbumin-spIgE levels were also high at 97 and 90 kU/L. The third patient's cow's milk-spIgE level was 15.9 kU/L, whereas the alpha-lactalbumin-spIgE level was 0.04 kU/L. Conclusion: Especially in patients with an initial reaction of anaphylaxis to dairy products and high cow's milk-spIgE levels, the risk of reaction is high with the MMR vaccine.

Safe administration of yellow fever vaccine in patients with suspected egg allergy

Background

The evidence available in the literature on the administration and safety of the yellow fever vaccine in patients with egg allergy is limited.

Objective

We sought to describe the administration of yellow fever vaccine in children with suspected egg allergy using a simplified protocol.

Methods

Children referred to the service from February 2018 to January 2020 with a history of possible egg allergy were classified as probably egg-allergic or not on the basis of history and specific IgE testing. A vaccine prick test was performed only in those with a history of an anaphylactic reaction to egg ingestion and if the result was positive the vaccine was administered in a 2-step protocol (2 equal doses of 0.25 mL with an interval of 30 minutes between the 2 applications). All other children received the vaccine as a single dose.

Results

A total of 435 children were evaluated; 48.27% were probably not allergic, and 51.72% were probably allergic to egg, of which 32.88% were considered anaphylactic. A total of 414 (95.2%) children had no vaccine reactions. Of the 21 (4.8%) children who had some reaction, 10 experienced a local reaction, 9 a mild skin reaction distant from the vaccine site, 1 presented local cutaneous reaction distant to the vaccination site, and 1 patient developed possible anaphylaxis. The vaccine prick test did not predict a vaccine reaction (odds ratio, 1.29; 95% CI, 0.25-6.72; P = .67).

Conclusions

Yellow fever vaccine can be safely administered as a single dose in children with a confirmed or suspected egg allergy.

Evaluation of vaccination status of children with special health care needs in Suzhou, China, 2020-2022: A retrospective survey study

Children with special health care needs (CSHCNs) are at an increased risk of vaccine-preventable infections (VPDs), but they also face the dilemma of vaccine hesitancy. We obtained information on pediatric visits from the Referral and Assessment Information System for Vaccination (RAISV) and information on vaccination from the Jiangsu Province Immunization Information System (JSIIS). We followed the occurrence of Adverse Events Following Immunization (AEFIs) and VPDs by actively calling and querying the China Information System for Disease Control and Prevention (CISDCP). The Poisson test was used to compare the incidence of AEFIs between groups. A total of 5,037 children who visited a vaccination assessment clinic were followed-up in this study. The majority were children with developmental anomalies (28.5%), certain conditions originating in the perinatal period (12.1%), and nervous system disorders (9.0%). Most CSHCNs (66.9%) were advised to have all vaccines according to routine practice, 29.0% were advised to have partial vaccination, and 4.1% were advised to delay all vaccines and wait for future assessment. A total of 201 (4.0%) CSHCNs were not vaccinated, although they were assessed to be eligible for vaccination. By querying the immunization planning module in CISDCP, we observed 55 AEFI cases, which amounted to an incidence rate of 1.2 per 1,000, and the occurrence of abnormal reactions was not significantly different compared with the general population. The vaccination program following the designed workflow for CSHCNs was safe and could be recommended in other areas.

Overdiagnosis of vaccine allergy: Skin testing and challenge at a public specialized unit (CRIE) in Rio de Janeiro, Brazil

Background

Vaccination is an extremely safe public health intervention, but rare IgE-mediated adverse events must be identified to avoid the risk of anaphylaxis in the event of reexposure. However, using only clinical history to diagnose previous allergic reactions may lead to overdiagnosis of vaccine allergy and even to the use of medical exemptions as a subterfuge to mandatory vaccination.

Methods

We conducted a retrospective study to describe the outcomes of patients with a history of vaccine or vaccine component allergy who were evaluated at our unit from 2011 to 2017. Data on allergy history, skin test results, vaccines prescribed, and adverse events were retrieved from the medical records at the Centro de Referência para Imunobiológicos Especiais (Reference Center of Special Immunobiologicals)-Fiocruz, in Rio de Janeiro, Brazil.

Results

Of 34 adults with history of allergy to vaccine or vaccine components, 32 (94.1%) were successfully vaccinated without serious adverse events after our evaluation. In 12 patients (35%), the time elapsed between the allergy symptoms and evaluation in the Centro de Referência para Imunobiológicos Especiais-Fiocruz was more than 10 years.

Conclusion

Specialized care and use of skin tests allowed safe vaccination of the majority of patients. An objective, systematic evaluation of a history of vaccine allergy can prevent its improper use to avoid mandatory vaccination and reduce missed opportunities for immunization.

Updated guidance regarding the risk of allergic reactions to COVID-19 vaccines and recommended evaluation and management: A GRADE assessment and international consensus approach

This guidance updates 2021 GRADE (Grading of Recommendations Assessment, Development and Evaluation) recommendations regarding immediate allergic reactions following coronavirus disease 2019 (COVID-19) vaccines and addresses revaccinating individuals with first-dose allergic reactions and allergy testing to determine revaccination outcomes. Recent meta-analyses assessed the incidence of severe allergic reactions to initial COVID-19 vaccination, risk of mRNA-COVID-19 revaccination after an initial reaction, and diagnostic accuracy of COVID-19 vaccine and vaccine excipient testing in predicting reactions. GRADE methods informed rating the certainty of evidence and strength of recommendations. A modified Delphi panel consisting of experts in allergy, anaphylaxis, vaccinology, infectious diseases, emergency medicine, and primary care from Australia, Canada, Europe, Japan, South Africa, the United Kingdom, and the United States formed the recommendations. We recommend vaccination for persons without COVID-19 vaccine excipient allergy and revaccination after a prior immediate allergic reaction. We suggest against >15-minute postvaccination observation. We recommend against mRNA vaccine or excipient skin testing to predict outcomes. We suggest revaccination of persons with an immediate allergic reaction to the mRNA vaccine or excipients be performed by a person with vaccine allergy expertise in a properly equipped setting. We suggest against premedication, split-dosing, or special precautions because of a comorbid allergic history.

Comparison of medium-term adverse reactions induced by the first and second dose of mRNA BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine: a post-marketing Italian study conducted between 1 January and 28 February 2021

OBJECTIVES

On 21 December 2020 the European Commission granted conditional marketing authorisation in the European Union for the anti-COVID-19 mRNA vaccine Bnt162b2 (Comirnaty, Pfizer/BioNTech). The main endpoint of this epidemiological, observational, prospective and monocentric study was to identify the number, types, and severity of adverse events following immunisation that occurred in subjects who had been previously infected with COVID-19, and in those who had not, after vaccination with Comirnaty, and to compare the two groups of subjects looking at events that occurred within a month after the first and the second dose.

METHODS

Data were gathered by a questionnaire. The results included the responses of all healthcare workers (2030) of the IRCCS Sacro Cuore Don Calabria Hospital (Italy) vaccinated between 1st January and 28th February 2021. Adverse effects of the vaccine were reported after the first and the second doses.

RESULTS

There was a statistically significant increase (p<0.001, χ2=35.60) in participants who experienced some side-effects after receiving the first dose of the vaccine and who had previously been infected with the coronavirus, compared with participants who had not previously been infected. 46.76% (136) of the participants who had previously been infected experienced some side-effects after the first dose of vaccine, and 63.23% (184) experienced some side-effects after the second dose, compared with 29.15% (507) after the first dose and 70.79% (1231) after the second dose in those who had not been previously infected. The number of participants who experienced side-effects after the second dose and had previously been infected was significantly lower compared with participants who had not previously been infected (p=0.0094, χ2=6.743).

CONCLUSIONS

Most of the side-effects identified in this trial were also reported by the manufacturer and the US Food and Drug Administration. Active surveillance should always continue to constantly check the vaccine's risk/benefit ratio over time.

Identifying and Managing Those at Risk for Vaccine-Related Allergy and Anaphylaxis

Immediate hypersensitivity reactions to vaccines, the most severe of which is anaphylaxis, are uncommon events occurring in fewer than 1 in a million doses administered. These reactions are infrequently immunoglobulin E-mediated. Because they are unlikely to recur, a reaction to a single dose of a vaccine is rarely a contraindication to redosing. This narrative review article contextualizes the recent knowledge we have gained from the coronavirus 2019 (COVID-19) pandemic rollout of the new mRNA platform with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines within the much broader context of what is known about immediate reactions to other vaccinations of routine and global importance. We focus on what is known about evidence-based approaches to diagnosis and management and what is new in our understanding of mechanisms of immediate vaccine reactions. Specifically, we review the epidemiology of immediate hypersensitivity vaccine reactions, differential diagnosis for immune-mediated and nonimmune reaction clinical phenotypes, including how to recognize immunization stress-related responses. In addition, we highlight what is known about mechanisms and review the rare but important contribution of excipient allergies and specifically when to consider testing for them as well as other key features that contribute to safe evaluation and management.

A practical guide to address reactions to vaccines in children

Currently available vaccines are safe, but, potentially, any vaccine can cause an allergic reaction and, albeit very rare, anaphylaxis can occur. Although its rarity, the precise diagnostic management of a suspected anaphylaxis postvaccination is of paramount importance due to the risk of a potentially serious reaction after re-exposure, while a misdiagnosis might lead to an increase in the number of children that interrupt vaccinations resulting in an unjustifiably individual and collective risk of loss of protection against immune preventable diseases. In the light that most cases of suspected allergy to a vaccine are not effectively confirmed in up to 85% of the cases referred for an allergy evaluation, patients can continue the vaccination schedule with the same formulation and tolerance of the booster doses. The patient assessment has to be done by an expert in the vaccine field, usually an allergist or an immunologist depending on the country, to select subjects at risk of allergic reactions and to perform the correct procedures for vaccine hypersensitivity diagnosis and management, in order to guarantee safe immunization practices. The aim of this review is to provide a practical guidance for the safe management of allergic children undergoing immunization procedures. The guide is referred both to the evaluation of children who have previously experienced a suspected allergic reaction to a specific vaccine and their management in case of further booster doses, and to children allergic to a component of the vaccine to be administered.

[Vaccination approach in patients with an allergic reaction to COVID-19 vaccines or at risk of developing allergic reactions]

Introduction

There is consensus that patients at risk of developing an allergic reaction to COVID-19 vaccines should be evaluated by an immunologist-allergist to determine whether vaccination should be recommended. We wanted to share our experiences in the management of these high-risk patients, from diagnostic tests in allergological evaluation to the vaccination process.

Materials and Methods

Our retrospective cross-sectional study included patients who had previously developed an allergic reaction to COVID-19 vaccines or drugs and therefore were referred to our allergy and immunology clinic. Prick and intradermal tests were performed on all patients with methylprednisolone acetate (Depo-Medrol®, Pfizer) 40 mg/mL containing polyethylene Glycol (PEG) and triamcinolone acetonide (Kenacort®, Deva) 40 mg/mL containing polysorbate 80. While vaccination with desensitization was recommended for all patients with positive skin tests, split-dose vaccination was recommended for patients with negative skin tests. After explaining the risks and benefits, the choice of the vaccine (Pfizer/BioNTech or Sinovac/ CoronoVac) was left to the patients' discretion.

Result

A total of 41 patients, 10 males, and 31 females, with a mean age of 42.37 ± 14.177 years were included. Eighteen patients with a history of allergy after COVID-19 vaccines were analyzed according to the type of reaction and type of vaccine administered (Pfizer/BioNTech/Coronovac; Anaphylaxis: 4/1, Urticaria: 11/2). Moreover, there was a history of drug allergy in 23 patients who had not been vaccinated before. Skin tests with PEG were positive in a total of seven patients while skin tests with polysorbate 80 were negative in all patients. No allergic reaction developed in seven patients who underwent desensitization and in 34 patients who received a split dose.

Conclusions

Considering the potentially life-saving benefits of vaccination in a global pandemic environment, it is a safe and effective method to administer vaccines to at-risk patients using desensitization or split dosing techniques, based on their sensitivity status determined through a PEG skin test. This approach allows for the avoidance of preventing access to vaccines, while still ensuring the safety of patients.

Anaphylaxis: Revision of the Brighton collaboration case definition

The Brighton Collaboration (BC) has formulated a number of case definitions which have primarily been applied to adverse events of special interest in the context of vaccine safety surveillance. This is a revision of the 2007 BC case definition for anaphylaxis. Recently, the BC definition has been widely used for evaluating reports of suspected anaphylaxis following COVID-19 vaccination. This has led to debate about the performance of the BC definition in comparison with those from the US National Institute of Allergy and Infectious Disease/Food Allergy Anaphylaxis Network (NIAID/FAAN) and the World Allergy Organization (WAO). BC convened an expert working group to revise the case definition based on their usual process of literature review and expert consensus. This manuscript presents the outcome of this process and proposes a revised case definition for anaphylaxis. Major and minor criteria have been re-evaluated with an emphasis on the reporting of observable clinical signs, rather than subjective symptoms, and a clearer approach to the ascertainment of levels of certainty is provided. The BC case definition has also been aligned with other contemporary and international case definitions for anaphylaxis.

Anaphylactic Reactions to COVID-19 Vaccines: An Updated Assessment Based on Pharmacovigilance Data

This study aimed at producing an updated assessment of the incidence of anaphylaxis associated with COVID-19 vaccines based on pharmacovigilance data. Anaphylactic reaction and anaphylactic shock data post-COVID-19-vaccination reported from week 52, 2020 to week 1 or week 2, 2023 were collected from the VAERS and EudraVigilance databases, respectively, and analyzed comparatively. Incidence rates were calculated using the corresponding administered vaccine doses as denominators for all licensed vaccines and both platform types (mRNA or vectored). The latest data from the present analysis showed lower anaphylaxis incidence associated with COVID-19 vaccination compared to previous estimates from week 52, 2020 to week 39, 2021 (anaphylactic reaction: 8.96 (95% CI 8.80-9.11)/million doses overall (EEA: 14.19 (95% CI 13.92-14.47)/million/US: 3.17 (95% CI 3.03-3.31)/million); anaphylactic shock: 1.46 (95% CI 1.39-1.52)/million doses overall (EEA: 2.47 (95% CI 2.36-2.58)/million/US: 0.33 (95% CI 0.29-0.38)/million)). Incidence rates varied by vaccine and were higher as captured in EudraVigilance compared to the VAERS and for vectored compared to mRNA vaccines. Most reported cases had a favorable outcome. The extremely rare fatalities (overall rates across continents 0.04 (95% CI 0.03-0.06)/million doses for anaphylactic reaction and 0.02 (95% CI 0.01-0.03)/million vaccine doses for anaphylactic shock) were also associated with vector-rather than mRNA-based vaccines. The diminished incidence of anaphylaxis post-vaccination with COVID-19 vaccines offers assurance about their safety, as does the continuous potential adverse events monitoring through specialized pharmacovigilance databases.

Anaphylaxis rates following mRNA COVID-19 vaccination in children and adolescents: Analysis of data reported to EudraVigilance

AIM

The present study aimed to estimate the anaphylaxis rates following mRNA COVID-19 vaccination in children and adolescents in Europe.

METHODS

We retrieved data on 371 anaphylaxis cases following mRNA COVID-19 vaccination in children ≤ 17 years old notified to EudraVigilance as of October 8, 2022. Overall, 27,120,512 doses of BNT162b2 vaccine and 1,400,300 doses of mRNA-1273 vaccine have been delivered to children during the study period.

RESULTS

The overall mean anaphylaxis rate was 12.81 [95% confidence interval (CI): 11.49-14.12] per 10⁶ mRNA vaccine doses [12.14 (95% CI: 6.37-17.91) per 10⁶ doses for mRNA-1273 and 12.84 (95% CI: 11.49-14.19) per 10⁶ doses for BNT162b2]. Children 12-17 years old accounted for 317 anaphylaxis cases, followed by 48 cases in children 3-11 years old, and 6 cases in children 0-2 years old. Children 10-17 years old had a mean anaphylaxis rate of 13.52 (95% CI: 12.03-15.00) cases per 10⁶ mRNA vaccine doses and children 5-9 years old had a mean anaphylaxis rate of 9.51 (95% CI: 6.82-12.20) cases per 10⁶ mRNA vaccine doses. There were two fatalities, both in the 12-17 years age group. The fatal anaphylaxis rate was 0.07 cases per 10⁶ mRNA vaccine doses.

CONCLUSIONS

Anaphylaxis is a rare adverse event after receiving an mRNA COVID-19 vaccine in children. Continuous surveillance of serious adverse events is needed to guide vaccination policies as we move towards SARS-CoV-2 endemicity. Larger real-world studies on COVID-19 vaccination in children, using clinical case confirmation, are imperative.

Allergic Reactions to Vaccines in Children: From Constituents to Specific Vaccines

Vaccination is an essential public health measure that helps to reduce the burden of infectious diseases in children. Although vaccines have an excellent safety record and the association of severe allergic reactions is rare, public concerns about vaccine safety can lead to incomplete vaccination coverage in children with or without allergies. Therefore, it is important to understand the mechanisms and implications of allergic reactions to vaccines and define strategies to manage them to provide the safest care for vaccine recipients. In this review, we provide an overview on the types of allergic reactions that can occur after vaccination, including those caused by various vaccine constituents. We also discuss the mechanisms underlying these allergic reactions and the recommended diagnosis and management strategies for children with a history of suspected allergic reactions to vaccines. An improved understanding of allergic reactions to vaccines can aid in the enhancement of the safety and effectiveness of vaccination.

Allergic adverse events following immunization: Data from post-marketing surveillance in Apulia region (South of Italy)

Introduction

Among adverse events following immunization (AEFIs), allergic reactions elicit the most concern, as they are often unpredictable and can be life-threatening. Their estimates range from one in 1,000,000 to one in 50,000 vaccine doses. This report describes allergic events following immunization reported from 2020 to 2021 in Puglia, a region in the South-East of Italy with around 4 million inhabitants. Its main objective is to describe the allergic safety profile of currently employed vaccines.

Materials and methods

This is a retrospective observational study. The study period spanned from January 2020 to December 2021, and the whole Apulian population was included in the study. Information regarding AEFIs reported in Puglia during the study period was gathered from the Italian Drug Authority's pharmacovigilance database (National Pharmacovigilance Network, RNF). The overall number of vaccine doses administered was extrapolated by the Apulian online immunization database (GIAVA). Reporting rates were calculated as AEFIs reported during a certain time span/number of vaccine doses administered during the same period.

Results

10,834,913 vaccine doses were administered during the study period and 95 reports of allergic AEFIs were submitted to the RNF (reporting rate 0.88/100,000 doses). 27.4% of the reported events (26/95) were classified as serious (reporting rate 0.24/100,000 doses). 68 out of 95 (71.6%) adverse events were at least partially resolved by the time of reporting and none of them resulted in the subject's death.

Conclusions

Allergic reactions following vaccination were rare events, thus confirming the favourable risks/benefits ratio for currently marketed vaccines.

Utilizing Biologics in Drug Desensitization

PURPOSE OF REVIEW

The purpose of this literature review was to review the latest advancements with biologics in rapid drug desensitization. Our methodology was to highlight both desensitization to biologics themselves and the use of biologics in desensitization to both biologic and nonbiologic drugs.

RECENT FINDINGS

Biologics are a vast category of drugs that include monoclonal antibodies, nanobodies, modern vaccinations, and even hormones. Desensitization to biologics can be safely performed through standardized procedure. Biomarkers are used both in vitro and in vivo to help identify and classify hypersensitivity reactions. Hypersensitivity reactions to the mRNA vaccinations against SARS-CoV-2 present their own unique challenges to management. There are specific excipients in monoclonal antibodies that are thought to be responsible for many of their hypersensitivity reactions. Certain biologics can even be used to assist in desensitization to other drugs. Rapid drug desensitization is a standardized procedure that may be able to help many patients who have experienced hypersensitivity reactions to biologics and would best be treated with them to continue to receive them. Biologic drugs have opened a new era in medicine for the prevention and treatment of infectious diseases, cancer, and inflammatory diseases. Hypersensitivity reactions to biologics are quite common. This literature review presents the latest advancements in our understanding of hypersensitivity reactions to biologics, how rapid drug desensitization can be used to continue therapy despite history of hypersensitivity, and how biologics themselves can be used to aid in desensitization itself.

COVID-19 vaccine provocation test outcome in high-risk allergic patients: A retrospective study from a tertiary hospital in Indonesia

Background

High COVID-19 vaccine coverage is essential. Patients who are considered high risk for hypersensitivity reactions and have had an allergic reaction to the COVID-19 vaccine are usually referred to an allergist for assessment of vaccination. Administration of a vaccine graded challenge (also known as a provocation test) is an option that can be considered in this population. This primary objective of this study is to describe the outcome of the COVID-19 vaccine provocation test and to understand the predicting factors associated with hypersensitivity reaction after the provocation test as the secondary objective.

Methods

Adult patients with a history of hypersensitivity reaction to the first COVID-19 vaccine and high-allergic patients who underwent COVID-19 vaccine provocation test up until May 2022 were included. A protocol using skin prick test (SPT), intradermal test (IDT), followed by graded challenge was developed for the determined vaccine used.

Results

A total of 232 patients were included in the analysis. Twenty-eight had hypersensitivity to their first COVID-19 vaccine dose and 204 were high risk for allergic reaction. Hypersensitivity reactions occurred in 20 patients (8.6%, 95% CI: 5-12.2%), consisting of 4 reactions after SPT, 9 after IDT, 7 during or after titrated challenge. Half of the reactions were mild; however, 3 patients developed severe reactions. Patients with history of anaphylaxis were more likely to experience hypersensitivity reaction after provocation test (aRR = 2.79, 95% CI: 1.05-7.42).

Conclusion

Provocation test in COVID-19 vaccination has a high success rate in patients with a history of hypersensitivity to the first COVID-19 vaccine and in high allergic patients. History of anaphylaxis is associated with hypersensitivity reaction after a COVID-19 vaccine provocation test.

Elicitors and phenotypes of adult patients with proven IgE-mediated food allergy and non-immune-mediated food hypersensitivity to food additives

BACKGROUND

Food allergy is a growing health concern with a prevalence of 2%-3% in the adult population in Europe. Non-immune-mediated food hypersensitivities, which include reactions after ingestion of food additives, affect 1% of adults and may resemble IgE-induced allergic reactions without identifiable immunologic sensitization. A double-blind placebo-controlled food challenge (DBPCFC) is the gold standard for the diagnosis of any food hypersensitivity.

OBJECTIVE

We analysed a large group of adult patients with suspected food hypersensitivity, who had undergone DBPCFC, to better understand IgE-mediated food allergy and non-immune-dependent food hypersensitivity to food additives in adults regarding elicitors, symptoms and positivity rates of oral challenges.

METHODS

Data from 541 patients with suspected food hypersensitivity were analysed, who underwent an oral food challenge between 2010 and 2019.

RESULTS

IgE-dependent food allergy was confirmed in 114 of 329 adult patients (34.6%). The confirmation rate was lower in the group of patients with suspected non-immune-mediated reactions to food additives (65 of 286, 22.7%). Urticaria and angioedema appeared more frequently in patients with IgE-mediated food allergies. By contrast, flush and diarrhoea were the most frequent symptoms after a challenge in the group with the non-immune-mediated reactions to food additives. Wheat and celery were the most frequently identified food allergens in adults, whereas colourings and preservatives were the most frequent elicitors of non-immune-mediated food hypersensitivity.

CONCLUSION

The importance of oral food challenges for the diagnosis of food hypersensitivity is confirmed. IgE-dependent food allergy is more frequently proven, reaching a positivity rate of one-third and only about 20% for non-immune-mediated hypersensitivity. Future studies should elaborate on the mechanisms of non-immune-mediated food hypersensitivity and the clinical impact of cofactors in this setting.

Revaccination and Adverse Event Recurrence in Patients with Adverse Events following Immunization

OBJECTIVES

To estimate the risk of recurrence of adverse events following immunization (AEFIs) upon revaccination and to determine among patients with suspected vaccine allergy whether allergy skin test positivity was associated with AEFI recurrence.

STUDY DESIGN

This prospective observational study included patients assessed in the Canadian Special Immunization Clinic Network from 2013 to 2019 with AEFIs who required revaccination with the vaccine temporally associated with their AEFI. Participants underwent standardized assessment and data collection. Special Immunization Clinic physicians used guidelines to inform their recommendations. Participants were followed up after revaccination to capture AEFI recurrences. Data were transferred to a central database for descriptive analysis.

RESULTS

Overall, 588 participants were assessed for 627 AEFIs; 570 (91%) AEFIs occurred in children <18 years of age. AEFIs included immediate hypersensitivity (130/627; 21%), large local reactions (110/627; 18%), nonurticarial rash (51/627; 8%), seizures (26/627; 4%), and thrombocytopenia (11/627; 2%). Revaccination was recommended to 513 of 588 (87%) participants. Among participants recommended and due for revaccination during the study period, 63% (299/477) were revaccinated. AEFI recurrence was 10% (31/299) overall, 31% (15/49) for large local reactions, and 7% (5/66) for immediate hypersensitivity. No recurrence was serious. Among 92 participants with suspected vaccine allergy who underwent skin testing and were revaccinated, the negative predictive value of skin testing for AEFI recurrence was 96% (95% CI 92.5%-99.5%).

CONCLUSIONS

Most individuals with AEFIs were safely revaccinated. Among those with suspected vaccine allergy, skin testing may help determine the safety of revaccination.

Anaphylaxis and allergic reactions to COVID‐19 vaccines: A narrative review of characteristics and potential obstacles on achieving herd immunity

Background and Aims

Methods

Results

Conclusion

Adverse Events and Safety of SARS-CoV-2 Vaccines: What's New and What's Next

Just over 1 year following rollout of the first vaccines for coronavirus disease 2019, 572 million doses have been administered in the United States. Compared with the number of vaccines administered, adverse effects such as anaphylaxis have been rare, and seemingly, the more serious the effect, the rarer the occurrence. Despite these adverse effects, there are few, if any, true contraindications to coronavirus disease 2019 vaccination and most individuals recover without further sequelae. This review provides guidance for the allergist/immunologist regarding appropriate next steps based on patient's known allergy history or adverse reaction after receipt of coronavirus disease 2019 vaccine to assist in safe global immunization.

Allergies and COVID-19 vaccines: An ENDA/EAACI Position paper

BACKGROUND

Anaphylaxis, which is rare, has been reported after COVID-19 vaccination, but its management is not standardized.

METHOD

Members of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interested in drug allergy participated in an online questionnaire on pre-vaccination screening and management of allergic reactions to COVID-19 vaccines, and literature was analysed.

RESULTS

No death due to anaphylaxis to COVID-19 vaccines has been confirmed in scientific literature. Potential allergens, polyethylene glycol (PEG), polysorbate and tromethamine are excipients. The authors propose allergy evaluation of persons with the following histories: 1-anaphylaxis to injectable drug or vaccine containing PEG or derivatives; 2-anaphylaxis to oral/topical PEG containing products; 3-recurrent anaphylaxis of unknown cause; 4-suspected or confirmed allergy to any mRNA vaccine; and 5-confirmed allergy to PEG or derivatives. We recommend a prick-to-prick skin test with the left-over solution in the suspected vaccine vial to avoid waste. Prick test panel should include PEG 4000 or 3500, PEG 2000 and polysorbate 80. The value of in vitro test is arguable.

CONCLUSIONS

These recommendations will lead to a better knowledge of the management and mechanisms involved in anaphylaxis to COVID-19 vaccines and enable more people with history of allergy to be vaccinated.

Management of suspected and confirmed COVID-19 (SARS-CoV-2) vaccine hypersensitivity

BACKGROUND

Systemic allergic reactions to vaccines are very rare. In this study we assessed the management and outcome of suspected SARS-CoV-2 vaccine hypersensitivity.

METHODS

Totally, 334 individuals underwent an allergy work up regarding SARS-CoV-2 vaccination (group A: 115 individuals suspected to be at increased risk for vaccine-related reactions before vaccination and group B: 219 patients with reactions after COVID vaccination). The large majority of the SPT/IDT with the vaccines were negative; however, we identified in 14.1% (n = 47) a possible sensitization to the SARS-CoV-2 vaccine and/or its ingredients defined as one positive skin test. Of the 219 individuals (group B) who experienced symptoms suspicious for a hypersensitivity reaction after vaccination, 214 were reported after the first vaccination with a mRNA vaccine (157 mRNA (Comirnaty®, 38 Spikevax®) and 18 with a vector vaccine (Vaxzevria®), 5 cases were after the second vaccination.

RESULTS

The symptom profile in group B was as follows: skin symptoms occurred in 115 cases (n = 59 angioedema, n = 50 generalized urticaria and n = 23 erythema/flush. Seventy individuals had cardiovascular, 53 respiratory and 17 gastrointestinal symptoms. Of the overall 334 individuals, 78 patients tolerated (re)-vaccination (out of skin test positive/negative 7/19 from group A and 17/35 from group B).

CONCLUSION

Proven IgE-mediated hypersensitivity to SARS-CoV-2 vaccines is extremely rare and not increased in comparison with reported hypersensitivity to other vaccines. The value of skin tests is unclear and nonspecific reactions, in particular when intradermal testing is applied, should be considered.

Anaphylaxis to additives in vaccines

Anaphylaxis in connection with the administration of vaccines occurs only very rarely. Triggers of immunoglobulin IgE-mediated and non-IgE-mediated anaphylaxis—in addition to the active ingredient itself—may be excipients contained in the vaccine due to their special properties. Some of the excipients in medicinal products are the same compounds used as additives in food. Furthermore, residues from the manufacturing process (e.g., chicken egg white, casein, antibiotics, formaldehyde) or contaminants (e.g., from the primary packaging material) may be potential triggers of anaphylaxis in vaccines. This review article provides an overview of ingredients in vaccines that pose an allergenic risk potential. The components of COVID-19 vaccines approved and marketed in Germany are discussed with regard to their potential for triggering anaphylaxis and possible pathophysiological mechanisms involved.

Anaphylaxie auf Zusatzstoffe in Impfstoffen

Anaphylaxien im zeitlichen Zusammenhang mit der Verabreichung von Impfstoffen treten nur sehr selten auf. Auslöser von IgE-vermittelten und nicht IgE-vermittelten Anaphylaxien können neben dem Wirkstoff selbst Hilfsstoffe sein, die aufgrund spezieller Eigenschaften im Impfstoff enthalten sind. Bei den Hilfsstoffen in Arzneimitteln handelt es sich teilweise um dieselben Verbindungen, die als Zusatzstoffe in Lebensmitteln eingesetzt werden. Weiterhin kommen in Impfstoffen Rückstände aus dem Herstellungsprozess (z. B. Hühnereiweiß, Kasein, Antibiotika, Formaldehyd) oder Kontaminationen (z. B. aus dem Primärpackmittel) als potenzielle Auslöser von Anaphylaxien in Frage. Der vorliegende Review gibt einen Überblick über Bestandteile in Impfstoffen, von denen ein allergenes Risikopotenzial ausgeht. Die Bestandteile der in Deutschland zugelassenen COVID-19-Impfstoffe als potenzielle Auslöser von Anaphylaxien und mögliche pathophysiologische Mechanismen werden diskutiert.

Zitierweise: Mahler V, Junker AC. Anaphylaxis to additives in vaccines. Allergo J Int 2022;31: 123-36

https://doi.org/10.1007/s40629-022-00215-8

COVID-19 vaccine counseling and safety assessment in children and teenagers with underlying medical conditions in China: a single center study

Safety concerns about novel vaccines and necessity of COVID-19 vaccination for children, especially with underlying medical conditions, are the obstacle of COVID-19 vaccination program among pediatric population. The study was conducted to investigate the vaccine hesitancy reasons among the parents, and to monitor the adverse events of inactivated COVID-19 vaccines in children and teenagers with underlying medical conditions in China. Children with underlying medical conditions encountered to the Immunization Advisory Clinic for COVID-19 vaccine counseling were enrolled. They were given immunization recommendation and followed up at 72 h and 28 d after immunization to monitor the immunization compliance after consultation and adverse events. A total of 324 children aged 3–17 y were included. The top three primary medical conditions for counseling were allergy (33.6%), neurological diseases (31.2%) and rheumatic diseases (8.3%). COVID-19 vaccination was promptly recommended for 242 (74.7%) children. Seventy-one (65.7%) children who had allergy issues were recommend to take vaccination, which was significantly lower than that of other medical conditions (p < .05). The follow-up record showed that 180 children received 340 doses of inactivated COVID-19 vaccine after consultation. Overall, 39 (21.6%) children reported at least one adverse event within 28 d of either vaccination. No serious adverse reactions were observed. No difference of adverse effects between the first dose and the second dose of vaccination except fever. Parents’ hesitancy in COVID-19 vaccination for children with underling medical conditions are mainly due to the safety concerns. Specialist consultation is helpful to improve the vaccine uptake.

Adverse Reactions to Anti-Infective Vaccines: an Emerging Problem in the COVID-19 Era

Purpose of review

Vaccines are an essential tool for preventing infectious diseases and reducing associated morbidity and mortality. Vaccination has a significant impact at both individual and community levels, and COVID‐19 vaccination programs are a new example of the great value of this public health strategy. However, adverse reactions, especially severe reactions such as anaphylaxis, prevent these programs from progressing properly, thus limiting vaccination uptake in the population.

Recent findings

The frequency of reactions and types of vaccine components, with special attention to COVID-19 vaccines studies, provides information on the magnitude and causes of adverse events. The understanding of mechanisms involved has made it possible to adequately guide diagnosis, especially to COVID-19 vaccine components, such as polyethylene glycol, trometamol, and polysorbate-80.

Summary

This review focuses on adverse reactions to vaccines, with emphasis on allergic reactions. A diagnostic pathway is suggested that, on the one hand, enables to take the necessary precautions in persons with a history of allergy to vaccine components or allergic reactions to vaccines and, on the other, supports administration of subsequent doses. The overall objective is to ensure that people with allergy can be vaccinated in the same way as the rest of the population, and that they are offered alternatives where necessary.

Immediate Hypersensitivity Reactions Induced by COVID-19 Vaccines: Current Trends, Potential Mechanisms and Prevention Strategies

As the world deals with the COVID-19 pandemic, vaccination remains vital to successfully end this crisis. However, COVID-19-vaccine-induced immediate hypersensitivity reactions presenting with potentially life-threatening systemic anaphylactic reactions are one of the reasons for vaccine hesitancy. Recent studies have suggested that different mechanisms, including IgE-mediated and non-IgE-mediated mast cell activation, may be involved in immediate hypersensitivity. The main culprits triggering hypersensitivity reactions have been suggested to be the excipients of vaccines, including polyethylene glycol and polysorbate 80. Patients with a history of allergic reactions to drugs, foods, or other vaccines may have an increased risk of hypersensitivity reactions to COVID-19 vaccines. Various strategies have been suggested to prevent hypersensitivity reactions, including performing skin tests or in vitro tests before vaccination, administering different vaccines for the primary and following boosters, changing the fractionated doses, or pretreating the anti-IgE antibody. This review discusses the current trends, potential mechanisms, and prevention strategies for COVID-19-vaccine-induced immediate hypersensitivity reactions.

Allergic Reactions After the Administration of COVID-19 Vaccines

Background

Data on allergic reactions after the administration of coronavirus disease (COVID-19) vaccines are limited. Our aim is to analyze reports of allergic reactions after COVID-19 vaccine administration.

Methods

The Vaccine Adverse Event Reporting System database was searched for reported allergic reactions after the administration of any of the COVID-19 vaccines from December 2020 to June 2021. After data mapping, the demographic and clinical characteristics of the reported cases were analyzed. Potential factors associated with anaphylaxis were evaluated using multivariable logistic regression models.

Results

In total, 14,611 cases were reported. Most cases of allergic reactions comprised women (84.6%) and occurred after the first dose of the vaccine (63.6%). Patients who experienced anaphylaxis were younger (mean age 45.11 ± 5.6 vs. 47.01 ± 6.3 years, P < 0.001) and had a higher prevalence of a history of allergies, allergic rhinitis, asthma, and anaphylaxis than those who did not (P < 0.05). A history of allergies (odds ratio (OR) 1.632, 95% confidence interval (CI) 1.467-1.816, P < 0.001), asthma (OR 1.908, 95%CI 1.677-2.172, P < 0.001), and anaphylaxis (OR 7.164, 95%CI 3.504-14.646, P < 0.001) were potential risk factors for anaphylaxis. Among the 8,232 patients with reported outcomes, 16 died.

Conclusions

Female predominance in allergic reaction cases after the receipt of COVID-19 vaccines was observed. Previous histories of allergies, asthma, or anaphylaxis were risk factors for anaphylaxis post-vaccination. People with these risk factors should be monitored more strictly after COVID-19 vaccination.

Utility and futility of skin testing to address concerns surrounding messenger RNA coronavirus disease 2019 vaccine reactions

BACKGROUND

The mechanism of coronavirus disease 2019 (COVID-19) vaccine hypersensitivity reactions is unknown. COVID-19 vaccine excipient skin testing has been used in evaluation of these reactions, but its utility in predicting subsequent COVID-19 vaccine tolerance is also unknown.

OBJECTIVE

To evaluate the utility of COVID-19 vaccine and vaccine excipient skin testing in both patients with an allergic reaction to their first messenger RNA COVID-19 vaccine dose and patients with a history of polyethylene glycol allergy who have not yet received a COVID-19 vaccine dose.

METHODS

In this multicenter, retrospective review, COVID-19 vaccine and vaccine excipient skin testing was performed in patients referred to 1 of 3 large tertiary academic institutions. Patient medical records were reviewed after skin testing to determine subsequent COVID-19 vaccine tolerance.

RESULTS

A total of 129 patients underwent skin testing, in whom 12 patients (9.3%) had positive results. There were 101 patients who received a COVID-19 vaccine after the skin testing, which was tolerated in 90 patients (89.1%) with no allergic symptoms, including 5 of 6 patients with positive skin testing results who received a COVID-19 vaccine after the skin testing. The remaining 11 patients experienced minor allergic symptoms after COVID-19 vaccination, none of whom required treatment beyond antihistamines.

CONCLUSION

The low positivity rate of COVID-19 vaccine excipient skin testing and high rate of subsequent COVID-19 vaccine tolerance suggest a low utility of this method in evaluation of COVID-19 vaccine hypersensitivity reactions. Focus should shift to the use of existing vaccine allergy practice parameters, with consideration of graded dosing when necessary. On the basis of these results, strict avoidance of subsequent COVID-19 vaccination should be discouraged.

Usability, acceptability, and feasibility of a High-Density Microarray Patch (HD-MAP) applicator as a delivery method for vaccination in clinical settings

Background

High-density microarray patch (HD-MAP) vaccines may increase vaccine acceptance and use. We aimed to ascertain whether professional immunizers (PIs) and other healthcare workers (HCWs) in Australia, a High-Income Country (HIC), found the HD-MAP applicator usable and acceptable for vaccine delivery.

Methods

This feasibility study recruited PIs and HCWs to administer/receive simulated HD-MAP administration, including via self-administration. We assessed usability against essential and desirable criteria. Participants completed a survey, rating their agreement to statements about HD-MAP administration. A subset also participated in an interview or focus group. Survey data were analyzed using descriptive statistics, and interviews were transcribed and subject to thematic analysis.

Results

We recruited 61 participants: 23 PIs and 38 HCWs. Findings indicated high usability and acceptability of HD-MAP use across both groups by a healthcare professional or trained user and for self-administration with safety measures in place. Most administrations met essential criteria, but PIs, on average, applied the HD-MAP for slightly less time than the required 10-seconds, which the HCWs achieved. PIs perceived safety concerns about home administration but found layperson self-administration acceptable in an emergency, pandemic, and rural or remote settings.

Conclusions

Participants found HD-MAP administration usable and acceptable. Usability and acceptability are likely to be improved through end-user education and training.

Professional immunizers and healthcare workers found high-density microarray patch devices highly usable and acceptable to administer vaccines.

HD-MAPs may have advantages over intramuscular injections in clinical settings and in pandemics.

Vaccination with HD-MAP may improve acceptance for those with needle-related anxiety.

Vaccinating with a COVID-19 Vaccine: Experience of the Tertiary Allergology Center

Background: Allergic reactions after messenger RNA (mRNA)-based COVID-19 vaccines have been reported but detailed descriptions and further actions are not well characterized. Objective: To describe the symptoms of possible allergic reactions after the mRNA COVID-19 vaccine and outcomes of further vaccination. Methods: We descriptively analyzed data of adult (≥18 years of age) patients, who were sent for vaccination to our outpatient center for the Diagnostics and Treatment of Allergic and Immune diseases. All patients were vaccinated with the Pfizer–BioNTech Comirnaty® vaccine.Results: From January 2021 to July 2021 twenty-two patients were vaccinated in our center. Six patients experienced a reaction after the first Comirnaty® dose in different vaccination centers. The majority of them complained of various types of rashes after the first dose, one case was consistent with anaphylaxis. The latter patient was tested with the skin prick using Pfizer–BioNTech Comirnaty® vaccine and the test was negative. Other sixteen patients were vaccinated in our center from the first dose because of past allergic reactions to other medication or due to concomitant mast cell disorder. All patients were vaccinated without any immediate adverse reactions.Conclusions: None of our patients experienced repeated cutaneous reactions after the second dose. Patients with previous anaphylaxis or mastocytosis also were safely vaccinated.

Proteomics for Development of Food Allergy Vaccines

Food allergy is a hypersensitivity reaction to food products initiated by immunologic mechanisms, which represents one of the major concerns in food safety. New therapies for food allergies including oral and epicutaneous allergen-specific immunotherapy are required, and B cell epitope-based allergy vaccines are a good promise to improve this field. In this chapter, we describe a workflow for the design of food allergy vaccines using proteomic tools. The strategy is defined based on the characterization of B cell epitopes for a particular food allergen. For that, the workflow comprises five consecutive steps: (1) shotgun proteomics analysis of different protein isoforms for a particular food allergen, (2) downloading all protein sequences for the specific allergen included in UniProtKB database, (3) analysis by protein-based bioinformatics of B cell epitopes, (4) synthesizing of the selected B cell peptide epitopes, and (5) performing of immunoassays using sera from healthy and allergic patients. The results from this method provide a rationale repository of B cell epitopes for the design of new specific immunotherapies for a particular food allergen. The strategy was optimized for all the beta-parvalbumins (β-PRVBs), which are considered as the main fish allergens. Using this workflow, a total of 35 peptides were identified as B cell epitopes, among them the top 4 B cell peptide epitopes that may induce protective immune response were selected as potential peptide vaccine candidates for fish allergy.

Vaccinating with a COVID-19 Vaccine: Experience of the Tertiary Allergology Center

BACKGROUND

Allergic reactions after messenger RNA (mRNA)-based COVID-19 vaccines have been reported but detailed descriptions and further actions are not well characterized.

OBJECTIVE

To describe the symptoms of possible allergic reactions after the mRNA COVID-19 vaccine and outcomes of further vaccination.

METHODS

We descriptively analyzed data of adult (≥18 years of age) patients, who were sent for vaccination to our outpatient center for the Diagnostics and Treatment of Allergic and Immune diseases. All patients were vaccinated with the Pfizer-BioNTech Comirnaty® vaccine.

RESULTS

From January 2021 to July 2021 twenty-two patients were vaccinated in our center. Six patients experienced a reaction after the first Comirnaty® dose in different vaccination centers. The majority of them complained of various types of rashes after the first dose, one case was consistent with anaphylaxis. The latter patient was tested with the skin prick using Pfizer-BioNTech Comirnaty® vaccine and the test was negative. Other sixteen patients were vaccinated in our center from the first dose because of past allergic reactions to other medication or due to concomitant mast cell disorder. All patients were vaccinated without any immediate adverse reactions.

CONCLUSIONS

None of our patients experienced repeated cutaneous reactions after the second dose. Patients with previous anaphylaxis or mastocytosis also were safely vaccinated.

Age-related differences in characteristics of anaphylaxis in Chinese children from infancy to adolescence

Background

Little is known about anaphylaxis in Chinese children. This study aimed to determine the age-specific patterns of anaphylaxis in Chinese children.

Methods

We conducted a retrospective study of anaphylaxis cases attending an allergy department in a tertiary children's hospital.

Results

A total of 279 anaphylactic reactions in 177 patients were analyzed. Overall, 57.6% (102/177) of first anaphylaxis events occurred in infants (0-2 ys). Foods were the most common culprits (88.5%), followed by food + exercise/exercise (4.7%), and drugs (4.3%). The main food allergens were cow's milk (32.9%), egg (21.4%), and wheat (20.7%) in infants, compared with fruits/vegetables at 35.9% in preschool-age children (3-6 ys) and 31.6% in school-age children (7-12 ys). The most commonly implicated drug triggers were vaccines (n = 5, comprising DTaP n = 2, group A + C meningococcal polysaccharide vaccine n = 1, Sabin vaccine n = 1, and not specified n = 1). Among the 5 vaccine-induced anaphylaxis patients, 4 had severe cow's milk allergy. The clinical manifestations were mainly mucocutaneous (86.0%), followed by respiratory (68.8%), gastrointestinal (23.7%), neurological (10.4%), and cardiovascular (0.7%). Compared with patients of other ages, infants had higher rates of hives (0-2ys 77.4%, 3-6ys 50%,7-12ys 57.9%, 13-17ys 38.9%, p = 0.016) and vomiting (0-2ys 20.7%, 3-6ys 1.6%,7-12ys 8.8%, p < 0.001), while wheezing was more frequent in school-age children (0-2ys 21.4%, 3-6ys 25%, 7-12ys 38.6%, 13-17ys 5.6%, p = 0.017) and abdominal pain was more common in adolescents (0-2ys 2.1%,3-6ys 15.6%, 7-12ys 14.0%, 13-17ys 72.3%, p < 0.001). Regarding treatment, 9.3% of anaphylaxis events and 24.1% of life-threatening reactions were treated with epinephrine.

Conclusions

We observed age-related clinical patterns of anaphylaxis in this study, with hives and vomiting most commonly reported in infants and cardiovascular symptoms rarely reported in children. Wheat was the third most culprit food allergen after egg and milk in infancy. Education regarding more aggressive use of epinephrine in the emergency setting is clearly needed. Recognition of age-related symptoms in anaphylaxis can aid physicians in prompt diagnosis and acute management.

Anaphylaxis rates associated with COVID-19 vaccines are comparable to those of other vaccines

We retrieved data on 8940 anaphylaxis cases post-COVID-19 vaccination from the US Vaccine Adverse Event Reporting System and the European EudraVigilance from week 52/2020 through week 31/2021 and compared them with those of other vaccines. Overall, 837,830,000 COVID-19 vaccine doses were delivered in the US and Europe during the study period, for which the vaccine name was known. The mean anaphylaxis rate was estimated at 10.67 cases per 10⁶ doses of COVID-19 vaccines (range: 7.99-19.39 cases per 10⁶ doses depending on the vaccine). COVID-19 vaccines ranked fifth in reported anaphylaxis rates, behind rabies, tick-borne encephalitis, measles-mumps-rubella-varicella, and human papillomavirus vaccines (70.77, 20, 19.8, and 13.65 cases per 10⁶ vaccine doses, respectively). COVID-19 vaccines are within the range of anaphylaxis rates reported across several common vaccines in these two passive reporting systems. These data should be communicated to reassure the general population about the safety profile of COVID-19 vaccines.

The role of community pharmacists in immunisation: a national cross-sectional study

Background Austrian pharmacists are not authorised to administer immunisations, and evidence about their willingness to immunise is lacking. Aim The aim of this study is to investigate Austrian community pharmacists’ willingness to administer immunisations in the future. Method This study is designed as a cross-sectional online survey based on the theoretical domains framework (TDF). The validated and piloted questionnaire obtained ethical approval by Robert Gordon University. Outcome measures included pharmacists’ willingness to immunise, service requirements, barriers and education needs. Results The questionnaire was sent out to 3086 community pharmacists of which 380 responses were included in the final analysis (12.3%). Willingness to administer immunisations after appropriate training and legislative regulation was stated by 82.6% (n = 314) of participants. It was demonstrated that pharmacists willing to immunise were significantly younger than their counterpart (38 [IQR 31–49] years vs. 45 [IQR 37.5–54] years; OR 1.06; 1.03–1.09, 95% CI; p < 0.001). ‘Legal liability’ was considered the most critical barrier to service implementation, ‘seeing blood’ and ‘close patient contact’ as least critical. Pharmacists not willing to immunise showed a higher probability to evaluate personnel resources (OR 2.98; 1.35–6.58, 95% CI; p = 0.007), close patient contact (OR 2.79; 1.46–5.34, 95% CI; p = 0.002) and management of side effects (OR 2.62; 1.21–5.67, 95% CI; p = 0.015) as (highly) critical. The majority assessed the ‘right timing for training’ to be after the foundation training with a 2-yearly renewal. Conclusion Austrian community pharmacists show a strong willingness to administer immunisations while highlighting important requirements and barriers towards service implementation.

SARS-CoV-2 vaccines-induced thrombotic thrombocytopenia: should we consider immuno-hypersensitivity?

The coronavirus disease 2019 (COVID-19) pandemic is significantly causing unprecedented clinical, socioeconomic, and public health challenges globally. The successful global administration of effective, safe and sustainable vaccine(s) is widely believed to be crucial in mitigating as well as preventing COVID-19. However, the rising cases of severe adverse events following immunization (AEFI) with COVID-19 vaccines including thrombosis, thrombocytopenia, and in some instances, death have created serious global concerns and could enormously contribute to vaccine hesitancy. Although the complete underlying pathophysiology and immunopathology of the COVID-19 vaccines related to AEFI, including thrombosis and/or anaphylaxis, are yet to be determined, exploring possible immuno-hypersensitivity could be crucial in the mechanisms associated with these reactions, thereby mitigating their occurrences as well as restoring confidence in vaccine administration for a COVID-19 free world.

CoronaVac COVID-19 Vaccine-Induced Anaphylaxis: Clinical Characteristics and Revaccination Outcomes

Anaphylaxis to CoronaVac, an inactivated vaccine against COVID-19, is extremely rare. We report 12 cases of anaphylaxis after CoronaVac administration, focusing on clinical characteristics and management outcomes. Skin test and graded vaccine challenge were successfully performed in our cases and might be considered if an inactivated vaccine is the only remaining option.

Allergic reactions against Covıd-19 vaccines

Coronavirus Disease 2019 (COVID-19) affected the whole world in a short time. One of the most influential public health initiatives modern medicine has to offer, the vaccine has become even more important as the COVID-19 pandemic continues to worsen worldwide. Many vaccine trials were launched during the COVID-19 pandemic, and these vaccines were widely used around the world, offering realistic hope for ending the pandemic. Allergic reactions to vaccines were reported shortly after their approval. These reactions, in general, are rare, but, in some circumstances, they can be serious. Allergy to vaccines can occur because of either the active vaccine component or vaccine ingredients. The spectrum of the reactions may be just a local hypersensitiviy reaction or may be as severe as an anaphylaxis, which is an acute severe, life-threatening systemic hypersensitive reaction, and it requires quick intervention. If an allergy is suspected, a correct examination followed by algorithms is important for true diagnosis, treatment, and decision regarding revaccination. Patients who experience an allergic reaction with the first dose of covid 19 vaccine should be directed to the allergy-immunologist, and the evaluation of at-risk patients should be individualized. Finally, we should point out that the benefits of current COVID-19 vaccines go far beyond the side effects, and that the vaccine is the most important way to recover from the pandemic.

Anaphylaxis and Coronavirus Disease 2019 vaccine: a danger relationship?

PURPOSE OF REVIEW

Anaphylactic reactions reported after Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) RNA vaccines were expected to be more frequent in atopic subjects and attributed to its polyethylene glycol component.

RECENT FINDINGS

Anaphylaxis to SARS-CoV2 RNA vaccines is no more frequent than in any vaccine and direct proofs for the role of its polyethylene glycol component are lacking.

SUMMARY

Vaccines against coronavirus disease 2019 (COVID-19) are an essential global intervention to control the current pandemic situation. Anaphylactic reactions have rapidly been reported after SARS-CoV2 RNA vaccines. This risk is now measured at 2.5-11/1 000 000 in the context of vaccine safety surveillance programs and only one case was documented to be due to polyethylene glycol. Suggestions for its role are indirect. The COVID-19 vaccination is rolling out vastly 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, highlighting the key role of allergists in the vaccination programmes.

The Risk of Allergic Reaction to SARS-CoV-2 Vaccines and Recommended Evaluation and Management: A Systematic Review, Meta-Analysis, GRADE Assessment, and International Consensus Approach

Concerns for anaphylaxis may hamper severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunization efforts. We convened a multidisciplinary group of international experts in anaphylaxis composed of allergy, infectious disease, emergency medicine, and front-line clinicians to systematically develop recommendations regarding SARS-CoV-2 vaccine immediate allergic reactions. Medline, EMBASE, Web of Science, the World Health Organizstion (WHO) global coronavirus database, and the gray literature (inception, March 19, 2021) were systematically searched. Paired reviewers independently selected studies addressing anaphylaxis after SARS-CoV-2 vaccination, polyethylene glycol (PEG) and polysorbate allergy, and accuracy of allergy testing for SARS-CoV-2 vaccine allergy. Random effects models synthesized the data to inform recommendations based on the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach, agreed upon using a modified Delphi panel. The incidence of SARS-CoV-2 vaccine anaphylaxis is 7.91 cases per million (n = 41,000,000 vaccinations; 95% confidence interval [95% CI] 4.02-15.59; 26 studies, moderate certainty), the incidence of 0.15 cases per million patient-years (95% CI 0.11-0.2), and the sensitivity for PEG skin testing is poor, although specificity is high (15 studies, very low certainty). We recommend vaccination over either no vaccination or performing SARS-CoV-2 vaccine/excipient screening allergy testing for individuals without history of a severe allergic reaction to the SARS-CoV-2 vaccine/excipient, and a shared decision-making paradigm in consultation with an allergy specialist for individuals with a history of a severe allergic reaction to the SARS-CoV-2 vaccine/excipient. We recommend further research to clarify SARS-CoV-2 vaccine/vaccine excipient testing utility in individuals potentially allergic to SARS-CoV2 vaccines or their excipients.

Immunization practices and risk of anaphylaxis: a current update, comprehensive of COVID-19 vaccination data

PURPOSE OF REVIEW

This review aims to provide an updated report in regards to the correlation between vaccines and anaphylaxis and the related risk in the population.

RECENT FINDINGS

Initial reports showed higher incidence of anaphylaxis following messenger RNA COVID-19 vaccines compared with 'routine' vaccinations, likely influenced by the great attention paid to these 'new' vaccines. However, anaphylaxis has still to be considered quite rare and its incidence will be systematically reconsidered in the light of additional data collected.

SUMMARY

Adverse reactions to vaccines are commonly reported but most of them are nonspecific mild events, whereas vaccine-related anaphylaxis is considered a rare event, with an incidence rate equal to 1.3 cases per million vaccine doses administered. As anaphylaxis reports usually start to be reported to passive pharmacovigilance during postmarketing surveillance, the first data are used to be influenced by under- and over-reporting and lack of denominators and following studies are needed to confirm the causal relationship. This might create an initial overcautiously approach to new immunization practices but, being anaphylaxis a potential life-threatening event, every suspected contraindication has to be deepened to maximize effectiveness and safety profile and constantly redefined not to exclude an overestimated population group who could receive the vaccine uneventfully.