Anaphylaxis: Revision of the Brighton collaboration case definition

Updates in Food Anaphylaxis Management

The management of food allergy has evolved over the past several years with regulatory approval of food allergy therapeutics as well as the common practice of oral immunotherapy. Whether a patient or family chooses one of these therapies or avoidance, they are still considered at risk of reaction, and thus clinicians still need to stay up to date with the latest advancements in the management of anaphylaxis in patients with food allergy. This review will highlight some of these updates, starting with the definition, diagnosis, and classifications of anaphylaxis. It will then review the latest updates in the management of food anaphylaxis in the community. Finally, the review will discuss the latest in epinephrine including recommendations on epinephrine dosing and novel routes of epinephrine administration.

Incidence and Factors Associated with Self-Reported Skin Symptoms of Allergic Reactions to COVID-19 Vaccines

Background: Few reports exist regarding the incidence and factors associated with allergic reactions to COVID-19 vaccines during post-marketing surveillance, especially for inactivated whole virus or viral vector vaccines. We aimed to determine the incidence and factors associated with self-reported allergic reactions to COVID-19 vaccines in the Thai population. Methods: A cross-sectional case-control study was conducted via telephone-based interviews. Cases were defined as physician-confirmed, self-reported vaccine recipients diagnosed with non-severe immediate allergic reactions, anaphylaxis, or delayed allergic reactions. Controls were randomly sampled from vaccinated individuals who reported no adverse events and were matched by the type of vaccine (1 case:2 controls). Demographic information and the history of atopic diseases were collected in both groups. Conditional logistic regression analysis was used to explore associated factors. Results: Among 215,079 vaccine doses administered, the incidence of self-reported skin symptoms of allergic reactions was 1821 events (0.85%). The risk factors for allergic reactions included age < 60 years (aOR 3.53; 95% CI:1.43-8.70; p = 0.006), female sex (aOR 8.33; 95% CI: 4.35-15.94; p < 0.001), a personal history of allergic rhinitis (aOR 4.32; 95% CI: 2.43-7.69; p < 0.001), atopic dermatitis (aOR 4.27; 95% CI: 1.74-10.47; p = 0.002), food allergies (aOR 6.53; 95% CI: 2.42-17.61; p < 0.001), and a family history of allergic disease (aOR 2.14; 95% CI: 1.12-4.08; p = 0.021). Conclusions: COVID-19 vaccines showed a low incidence of self-reported allergic reactions, which were more likely to occur in younger individuals, females, and those with a history of atopic diseases.

Anaphylaxis versus inducible laryngeal obstruction: a diagnostic dilemma

Inducible laryngeal obstruction (ILO) is an under-recognised cause of refractory breathlessness. It presents with an acute onset of difficulty in breathing and is often mistaken for respiratory conditions such as asthma or, in some cases, anaphylaxis. People with ILO often report recurrent Accident & Emergency attendances and have long-term drug treatments initiated and escalated inappropriately. The cornerstone of ILO management is speech and language therapy, and it is essential that cases are identified promptly to ensure they are managed correctly. By doing this, patients can be supported with education and therapeutic strategies, thus reducing associated distress, unnecessary pharmacotherapy and overall healthcare utilisation. In this case study, we describe a patient who was diagnosed and successfully treated for ILO after initially being investigated for recurrent anaphylaxis. She had a significant symptom burden with multiple hospital admissions and relied on epinephrine to manage these episodes. Following specialist assessment and treatment, she was subsequently weaned off potentially dangerous medications that were not clinically indicated, while reporting a marked improvement in her quality of life (see Patient's perspective below).

Safety comparison between Pfizer BNT162b2, Moderna mRNA-1273, and AstraZeneca AZD1222 in a Nationwide prospective cohort survey at the beginning of the severe acute respiratory syndrome coronavirus 2 vaccination in Japan

This study was conducted at 112 government and Juntendo University hospitals in February 2021 for the primary series of SARS-CoV-2 vaccinations. We compared the timing of solicited adverse event (AE) onset and prevalence of unsolicited AEs for Pfizer, Moderna, and AstraZeneca vaccines in a nationwide, large-scale prospective cohort study. The Pfizer and Moderna mRNA vaccines were associated with a higher frequency of fever after the second dose than after the first dose. The AstraZeneca viral vector vaccine resulted in more frequent side effects after the first dose. The side effects of mRNA vaccines were the most common on the day after vaccination and almost subsided by the fourth day. The incidence of systemic AEs, including fever of ≥37.5 °C, was the highest for Moderna, followed by AstraZeneca and Pfizer. Local reactions were less frequent with the AstraZeneca vaccine than with the Pfizer and Moderna vaccines but tended to last longer. The frequency of AEs was higher in women than in men. The odds ratio for age per year regarding systemic reactions (adjusted for sex) was the least for AstraZeneca, followed by Pfizer and Moderna (< 1), indicating a more pronounced decrease in the frequency of fever and systemic reactions with increasing age. Age effects varied among vaccines. Delayed skin reactions, appearing around the seventh day after the first dose (Day 8), were observed as itchy redness, particularly in women aged ≥30 with the Moderna vaccine and less often with the Pfizer vaccine. Over half of the delayed skin reactions involved local erythema immediately after the second dose, but these reactions mostly disappeared within approximately 10 days. Despite differences in the incidence of AEs among the three vaccines by age and sex, all vaccines were well-tolerated. These findings provide crucial safety information, supporting informed vaccination decisions and ongoing surveillance efforts.

Post-licensure Safety Surveillance of 20-Valent Pneumococcal Conjugate Vaccine (PCV20) Among US Adults in the Vaccine Adverse Event Reporting System (VAERS)

BACKGROUND

On June 8, 2021, a new 20-valent pneumococcal conjugate vaccine (PCV20, PREVNAR 20®, Pfizer, Inc.) was licensed for use in adults aged ≥ 18 years by the US Food and Drug Administration (FDA).

OBJECTIVE

To describe reports to the Vaccine Adverse Event Reporting System (VAERS) after administration of the 20-valent pneumococcal conjugate vaccine in adults.

METHODS

We searched the VAERS for reports of adverse events involving persons aged ≥ 19 years who received PCV20 during October 20, 2021, through December 31, 2023. Our evaluation included automated analysis of reports, clinical review of serious reports and pre-specified events of special interest, empirical Bayesian data mining to assess for disproportionate reporting, and estimation of reporting rates for reports of Guillain-Barré syndrome (GBS).

RESULTS

The VAERS received 1976 reports after PCV20 administration in persons aged ≥ 19 years (6% of reports involved serious events). The most common adverse events among persons aged 19-64 years (n = 798) were injection-site reactions (231, 29%), pain (134, 17%), erythema (118, 15%), and fever (117, 15%). For persons aged ≥ 65 years (n = 1178), the most common adverse events were injection-site reactions (417, 35%), pain (180, 15%), pain in extremity (162, 14%), and erythema (158, 13%). A data mining alert (EB05 = 3.812) for the MedDRA Preferred Term "Guillain-Barre syndrome" was observed for serious reports. Clinical review verified 11 of 20 GBS reports; 7/11 vaccine recipients were aged ≥ 65 years. Among the 11 verified cases, the median time from vaccination to symptom onset was 14 days. Five persons received another vaccine on the same visit. The reporting rate of GBS after PCV20 receipt was 0.5 cases per million doses distributed. No other safety concern was identified.

CONCLUSIONS

During the period of this post-licensure review of PCV20, we found most reports were non-serious and comprised mostly local and systemic (e.g., fever) reactions consistent with prelicensure studies. In serious reports, we also identified a data mining alert for GBS after receipt of PCV20, which Centers for Disease Control and Prevention and the FDA are investigating further. No other new or unexpected safety concern was identified.

Safety signal detected: Anaphylaxis after attenuated dengue vaccine (TAK-003) - Brazil, march 1, 2023-march 11, 2024

The aim was to describe cases of anaphylaxis following the Attenuated Dengue Vaccine (TAK-003) in Brazil, from March 1, 2023, to March 11, 2024. A descriptive study of anaphylaxis cases following TAK-003 was conducted, as reported in the National System of Surveillance of Adverse Events Following Immunization (AEFI). Percentages and notification rates of AEFI per million doses administered (DA) were calculated. In total, 380,358 doses of TAK-003 were administered, and 626 AEFI were reported. Of these, 85 were cases of immediate hypersensitivity, with 24 (63.1 cases per million) being anaphylaxis, including three anaphylactic shock. For 10 (41.7 %) cases, reactions began within 15 min after vaccination. No deaths related to anaphylaxis were reported. In light of the safety signal identification (increased frequency of anaphylaxis post-dengue vaccination), the Ministry of Health of Brazil published recommendations for intensifying actions for safe vaccination, including healthcare professional training and post-vaccination observation.

mRNA COVID-19 vaccine safety among children and adolescents: a Canadian National Vaccine Safety Network cohort study

Background

The Canadian National Vaccine Safety Network conducted active safety surveillance for COVID-19 vaccines. This study aimed to characterize the short-to-medium term safety of mRNA COVID-19 vaccines across the pediatric age spectrum.

Methods

In this cohort study, vaccinated and unvaccinated children and adolescents aged 6 months to 19 years from eight Canadian provinces and territories were invited to participate. The outcome was a health event preventing daily activities, resulting in school absenteeism, or requiring medical consultation. Age-stratified multivariable regression models were used to examine health events associated with first and second doses of mRNA COVID-19 vaccines across different age groups: children under 5, children aged 5-11 years and adolescents aged 12-19 years.

Findings

From January 2021 through February 2023, a total of 259,361 individuals from the dose one survey, 131,032 from the dose 2 survey, and 1179 from the control survey were included. In the week following dose two, vaccinated adolescents showed a higher proportion of health events [794 (4.6%) of 17,218 BNT162b2 recipients, 98 (8.5%) of 1153 mRNA-1273 recipients, 49 of (10.6%) of 464 heterologous schedule recipients] than unvaccinated adolescents [9 (3.7%) of 242 controls], but most events were self-limited and resolved within 7 days. No significant differences in proportion of health events following mRNA COVID-19 vaccines were observed between vaccinated and unvaccinated groups among adolescents after dose 1, or among children under 5 or those aged 5-11 years after any dose. Reported myocarditis/pericarditis cases within 0-28 days peaked among male adolescents following dose 2, in three of (0.037%) 8088 homologous BNT162b2 recipients, and two of (0.529%) 378 homologous mRNA-1273 recipients.

Interpretation

Our findings suggest that reported health events, including myocarditis/pericarditis, vary by pediatric age group. Vaccinated adolescents reported health events more frequently following the second mRNA COVID-19 vaccine dose, while younger age groups did not report events more frequently than their unvaccinated counterparts.

Funding

Canadian Immunization Research Network, Canadian Institutes of Health Research; Public Health Agency of Canada; COVID-19 Immunity Task Force.

Epidemiology, Risk Factors, and Management of Biphasic Anaphylaxis

PURPOSE OF REVIEW

Biphasic anaphylaxis is a variant of anaphylaxis characterized by recurrence of symptoms after initial resolution of anaphylaxis. It was first described in the mid 1990s by Popa and Lerner. Our understanding of the pathophysiology and epidemiology of the condition has advanced considerably since then. The purpose of this manuscript is to review the literature surrounding biphasic anaphylaxis while highlighting key works and recent advances.

RECENT FINDINGS

Prior studies have estimated biphasic anaphylaxis occurs in 0.4-20% of anaphylaxis episodes. The wide range may be related to differences in anaphylaxis diagnostic criteria which was inconsistent across studies. Recently identified risk factors for occurrence of biphasic anaphylaxis include severe initial symptoms including hypotension or hypoxia, delay in epinephrine use, and greater than one dose of epinephrine required to treat symptoms. Despite our progress to better understand biphasic anaphylaxis, there remain gaps in the literature. This article aims to review the recent literature including, epidemiology, risk factors, and management of biphasic anaphylaxis.

JYNNEOS vaccine safety surveillance in the vaccine safety datalink during the 2022 mpox outbreak in the United States

BACKGROUND

The JYNNEOS vaccine (two doses given 28 days apart) was recommended in the United States for people at high risk of exposure to monkeypox virus during the 2022 mpox outbreak. Our objective was to assess the safety of JYNNEOS using two complementary epidemiologic methods.

METHODS

This observational cohort included patients of eight large integrated healthcare organizations who received JYNNEOS. Adverse events were identified using ICD-10 coded diagnoses assigned to medical visits. The first analysis used standardized incidence ratios (SIR) to compare the observed incidence of ten prespecified adverse events of special interest (AESI) during the 28 days after receipt of each dose of JYNNEOS to the expected incidence adjusted for several risk factors. The second analysis used tree-based data mining to identify temporal clustering of cases for more than 60,000 diagnoses and diagnosis groups within 70-days after JYNNEOS dose 1 administration.

RESULTS

The SIR analysis included 53,583 adults who received JYNNEOS dose 1 and 38,206 who received dose 2. Males received 92% of the doses. There were no statistically significant elevated SIRs for any of the ten AESI. The tree-based data mining analysis included 36,912 vaccinees. Analysis of diagnoses in inpatient, emergency department, and outpatient settings identified statistically significant clusters of visits for rash and unspecified adverse effects.

CONCLUSIONS

No new or unexpected safety concerns were identified. AESI did not occur more frequently than expected by chance alone. Non-serious medically attended adverse events, such as rash, have been previously reported and occurred infrequently.

Applicability of selected Brighton Collaboration case definitions in low-resource settings: A prospective hospital-based active surveillance in Addis Ababa, Ethiopia

INTRODUCTION

Standardizing case definitions for priority vaccine safety conditions facilitates uniform evaluation and consolidation of data obtained from different settings. The Brighton Collaboration case definitions (BCCD) were created to support this harmonization and enable classification from level 1 (most certain) to level 5 (not a case) of certainty. Assessing the performance of BCCD in practice is critical, particularly in resource-limited settings, where many new vaccines may be introduced without prior monitoring in high-income countries. We assessed the performance of BCCD in Addis Ababa, Ethiopia, as applicable to COVID-19 and other vaccines.

METHODS

Active surveillance was conducted at Tikur Anbessa Specialized Hospital, the largest referral hospital in Ethiopia. During June 1, 2022-May 31, 2023, three trained physicians prospectively identified patients eligible for COVID-19 vaccination (regardless of vaccine receipt) who presented with one or more of eleven pre-specified adverse events of special interest (AESI) from the emergency department and inpatient wards. Standardized data collection forms were used to capture patient information and assign level of certainty (LOC), regardless of vaccination status for COVID-19. We conducted descriptive analysis to characterize cases and the LOCs reached for each AESI.

RESULTS

We detected 203 AESI cases. The most detected conditions were thrombosis and thromboembolism (n = 100, 49 %) and generalized convulsions (n = 38, 19 %). Ninety-six percent of the cases were confirmed at levels 1-3 (n = 187) or level 5 (n = 9) LOC. Non-classifiable (level 4) cases were observed for pericarditis (n = 2), encephalitis (n = 2), myelitis (n = 2), and generalized convulsion (n = 1).

CONCLUSION

The BCCD were successfully applied in > 95 % of cases in a large referral hospital in Ethiopia, with generalized convulsion, pericarditis, and encephalomyelitis as the exceptions. We recommend further evaluation in other low-resource settings, particularly in rural or non-referral hospitals, to gain additional insights into performance of these definitions for revision or adaptation, as needed.

Revaccination outcomes among adolescents and adults with suspected hypersensitivity reactions following COVID-19 vaccination: A Canadian immunization research network study

BACKGROUND

COVID-19 vaccination has been associated with anaphylaxis and hypersensitivity reactions. Infectious disease physicians and allergists in the Canadian Special Immunization Clinic (SIC) Network developed guidance for evaluating patients with adverse events following immunization (AEFI) including suspected hypersensitivity. This study evaluated management and adverse event recurrence following subsequent COVID-19 vaccinations.

METHODS

Individuals aged 12 years and older enrolled at participating SICs before February 28, 2023 who were referred for suspected or diagnosed hypersensitivity reaction following COVID-19 vaccination, or for prevaccination assessment of suspected allergy to a COVID-19 vaccine component were included. De-identified clinical assessments and revaccination data, captured in a centralized database, were analyzed. The Brighton Collaboration case definition (BCCD) for anaphylaxis (2023 version) was applied.

RESULTS

The analysis included 206 participants from 13 sites: 26 participants referred for pre-vaccination assessment and 180 participants referred for adverse events following COVID-19 vaccination (15/180 [8.3%] with BCCD confirmed anaphylaxis, 84 [46.7%] with immediate hypersensitivity symptoms not meeting BCCD, 33 [18.3%] with other diagnosed hypersensitivity reactions, and 48 [26.7%] participants with a final diagnosis of non-hypersensitivity AEFI). Among participants referred for AEFIs following COVID-19 vaccination, 166/180 (92.2%) were recommended for COVID-19 revaccination after risk assessment, of whom 158/166 (95.2%) were revaccinated (all with a COVID-19 mRNA vaccine). After revaccination, 1/15 (6.7%) participants with prior anaphylaxis, 1/77 (1.3%) with immediate hypersensitivity not meeting criteria for anaphylaxis and 1/24 (4.2%) with other physician diagnosed hypersensitivity developed recurrent AEFI symptoms that met the BCCD for anaphylaxis. All 26 participants referred pre-vaccination, including 9 (34.6%) with history of polyethylene glycol-asparaginase reactions, were vaccinated without occurrence of immediate hypersensitivity symptoms.

CONCLUSIONS

Most individuals in this national cohort who experienced a hypersensitivity event following COVID-19 vaccination and were referred for specialist review were revaccinated without AEFI recurrence, suggesting that specialist evaluation can facilitate safe revaccination.

Safety of COVID-19 Vaccines among People with History of Allergy: A European Active Surveillance Study

Background: Conventional vaccines rarely cause severe allergic reactions. However, the rapid development and approval of COVID-19 vaccines left limited initial data on their adverse reactions, particularly in individuals with a history of allergy. The aim of this study was to assess and compare the safety profile of different doses and brands of COVID-19 vaccines in subjects with a history of allergy vs. those without a history of allergy. Methods: From February 2021 to February 2023, a web-based prospective study gathered vaccinee-reported outcomes using electronic questionnaires across eleven European countries. Baseline and up to six follow-up questionnaires captured data on vaccinee demographics, as well as both solicited and unsolicited adverse reactions. Results: Overall, 3476 vaccinees with a history of allergy were matched with 13,872 vaccinees from the general population at the first vaccination cycle and were included in the analysis. A total of 825 vaccinees with a history of allergy who had received a booster dose, matched to 3297 vaccinees from the general population, were included in the analysis. Higher rates of ADRs occurred after the first vaccination cycle compared to after the booster dose (64-91% vs. 56-79%). However, most reported ADRs were solicited and not serious, and no case of anaphylaxis was reported. Women and vaccinees with a history of allergy reported ADRs more frequently than men and the matched controls, respectively. Compared to other COVID-19 vaccines, a higher proportion of vaccinees experiencing at least one ADR following their first vaccination cycle was observed with Comirnaty and Vaxzevria. Statistically significant differences were observed among the study cohorts for median TTO after the second dose, and for median TTR following the first vaccination cycle and booster dose (p < 0.001). Conclusions: Typically, any drug or vaccine use carries a risk of severe allergic reactions, yet the benefits of vaccination generally outweigh these potential risks, as shown with the COVID-19 vaccines.

JYNNEOS Vaccine Safety Surveillance During the 2022 Mpox Outbreak Using the Vaccine Adverse Event Reporting System and V-safe, United States, 2022 to 2023

BACKGROUND

In response to the 2022 mpox outbreak in the United States, people with higher potential for exposure to mpox were recommended to receive 2 doses of the JYNNEOS vaccine. Vaccine safety was monitored using 2 complementary systems.

METHODS

The Vaccine Adverse Event Reporting System (VAERS) is a passive surveillance system that accepts reports of adverse events after vaccination. VAERS is capable of rapidly identifying rare adverse events and unusual reporting patterns. Medical records were requested and reviewed for adverse events of special interest, including myocarditis. Adverse event reporting rates were calculated as the number of verified adverse event cases divided by the number of JYNNEOS doses administered. V-safe for mpox was a voluntary smartphone-based vaccine safety surveillance system that sent enrolled persons text messages linked to health surveys asking about reactions and health impact events occurring after vaccination.

RESULTS

There were 1,207,056 JYNNEOS doses administered in the United States. VAERS received 1927 reports for JYNNEOS. The myocarditis reporting rate per million doses was 2.69 after dose 1 and 8.64 after dose 2. V-safe had 213 participants complete at least one health survey. Rates of injection site and systemic reactions were similar in the first week after dose 1 and dose 2.

CONCLUSIONS

JYNNEOS vaccine safety surveillance findings from VAERS and v-safe did not identify any unexpected safety concerns. The VAERS reporting rate for myocarditis was similar to previously published population background rates.

Anaphylaxis: Definition and criteria

Anaphylaxis is a systemic allergic reaction that may be severe and life-threatening. With more than a dozen anaphylaxis definitions proposed over the past several decades and several diagnostic criteria in circulation, there is a need for a multinational consensus definition to simplify management across specialties. Anaphylaxis diagnostic criteria are more alike than they are different, and approaches of the National Institute of Allergy and Infectious Disease, World Allergy Organization, and Brighton Collaborative help to add granularity and perspective to patient management. Anaphylaxis occurs across a spectrum of severity within populations, although, among individual patients, there is some evidence to suggest more consistency for an individual allergen. Still, severity is influenced by a number of factors that demonstrate variability: factors that relate to allergen triggers, patient characteristics, and treatments received. Severity of anaphylaxis impacts management, and recent guidelines provide approaches that consider individual factors to inform both strong and conditional recommendations. Conditional recommendations serve as navigational signals for shared decision-making when patient expertise is leveraged to inform individual preferences and values together with clinician expertise in anaphylaxis management to provide patient care bespoke to each patient. As novel approaches to both prevention and treatment of anaphylaxis emerge, an understanding of the significance of strong and conditional recommendations becomes critical to providing individualized and appropriate care for patients at risk for anaphylaxis.

A randomized double-blinded trial to assess recurrence of systemic allergic reactions following COVID-19 mRNA vaccination

BACKGROUND

Systemic allergic reactions (sARs) following coronavirus disease 2019 (COVID-19) mRNA vaccines were initially reported at a higher rate than after traditional vaccines.

OBJECTIVE

We aimed to evaluate the safety of revaccination in these individuals and to interrogate mechanisms underlying these reactions.

METHODS

In this randomized, double-blinded, phase 2 trial, participants aged 16 to 69 years who previously reported a convincing sAR to their first dose of COVID-19 mRNA vaccine were randomly assigned to receive a second dose of BNT162b2 (Comirnaty) vaccine and placebo on consecutive days in a blinded, 1:1 crossover fashion at the National Institutes of Health. An open-label BNT162b2 booster was offered 5 months later if the second dose did not result in severe sAR. None of the participants received the mRNA-1273 (Spikevax) vaccine during the study. The primary end point was recurrence of sAR following second dose and booster vaccination; exploratory end points included biomarker measurements.

RESULTS

Of 111 screened participants, 18 were randomly assigned to receive study interventions. Eight received BNT162b2 second dose followed by placebo; 8 received placebo followed by BNT162b2 second dose; 2 withdrew before receiving any study intervention. All 16 participants received the booster dose. Following second dose and booster vaccination, sARs recurred in 2 participants (12.5%; 95% CI, 1.6 to 38.3). No sAR occurred after placebo. An anaphylaxis mimic, immunization stress-related response (ISRR), occurred more commonly than sARs following both vaccine and placebo and was associated with higher predose anxiety scores, paresthesias, and distinct vital sign and biomarker changes.

CONCLUSIONS

Our findings support revaccination of individuals who report sARs to COVID-19 mRNA vaccines. Distinct clinical and laboratory features may distinguish sARs from ISRRs.

Analysis of Allergy and Hypersensitivity Reactions to COVID-19 Vaccines According to the EudraVigilance Database

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic presented a new challenge in modern medicine: the development of vaccines was followed by massive population vaccinations. A few reports on post-vaccination allergic reactions have made patients and medical personnel uneasy as to COVID-19 vaccines' allergic potential. Most of the studies in this area to date have been small, and some that were based on global databases skipped most of the allergic diseases and concentrated only on anaphylaxis. We aimed to analyze the incidence of serious allergic reactions based on the EudraVigilance (EV) database, regardless of the reported symptoms and allergy mechanism.

METHODS

The total number of administrated vaccine doses was extracted on 5 October 2023 from Vaccine Tracker and included all administrations since vaccinations began in the European Economic Area (EEA). Data on serious allergic reactions to COVID-19 vaccines were extracted from the EudraVigilance database with the same time point. The code names of 147 allergic symptoms or diseases were used.

RESULTS

The frequency of serious allergic reactions per 100,000 administered vaccine doses was 1.53 for Comirnaty, 2.16 for Spikevax, 88.6 for Vaxzevria, 2.11 for Janssen, 7.9 for Novavax, 13.3 for VidPrevtyn Beta, and 3.1 for Valneva. The most prevalent reported reactions were edema (0.46) and anaphylaxis (0.40). Only 6% of these reactions were delayed hypersensitivity-oriented.

CONCLUSIONS

The overall frequency of potential serious allergic reactions to COVID-19 is very rare. Therefore, COVID-19 vaccines seem to be safe for human use. The lowest frequency of allergic reaction was observed for Comirnaty and the highest for Vaxzevria.

Safety and Tolerability of COVID-19 Vaccine in Mast Cell Disorders Real-Life Data from a Single Centre in Italy

Background In the past three years, COVID-19 has had a significant impact on the healthcare systems and people's safety worldwide. Mass vaccinations dramatically improved the health and economic damage caused by SARS-CoV-2. However, the safety of COVID-19 vaccines in patients at high risk of allergic reactions still has many unmet needs that should be clarified. Material and methods A retrospective, single-centre study was performed by collecting demographic and clinical data of patients with Mast Cell Disorders (MCDs) to evaluate the safety and tolerability of COVID-19 vaccinations. Moreover, any changes in the natural history of the underlying disease following the vaccine have been evaluated. Results This study included 66 patients affected with MCDs. Out of them, 52 (78.8%) received a COVID-19 vaccination and 41 (78.8%) completed the vaccination course. Premedication came first in 86.6% of our patients. A total of seven (4.5%) patients complained about an immediate reaction and two (1.3%) had a late reaction. Worsening of MCD history was observed in a single patient. Conclusions Despite the overall high risk of allergic reactions, our study did not reveal any increased risk for SARS-CoV-2 allergic reactions in MCD patients, thus supporting the recommendation in favour of the SARS-CoV-2 vaccination. However, due to the potentially increased rate of anaphylactic reactions, MCD patients should receive vaccine premedication and should be treated in a hospital setting after an allergological specialistic evaluation.

Gastrointestinal reflux contributes to laryngopharyngeal symptoms that mimic anaphylaxis: COVID-19 vaccination experience

Background

The sensation of throat closure after vaccination is concerning for anaphylaxis and leads to vaccine hesitancy.

Objectives

We characterized patients who developed laryngopharyngeal symptoms (LPhS) after coronavirus disease 2019 (COVID-19) vaccination and assessed risk factors for these symptoms.

Methods

The study analyzed data from the COVID-19 vaccines adverse reactions registry (December 14, 2020, to June 13, 2022). Outcomes included the incidence of postvaccination LPhS and use of epinephrine. We identified and compared risk factors for COVID-19 postvaccination reactions between subjects with and without LPhS.

Results

A total of 158 subjects were enrolled onto the registry. LPhS were reported in 61 subjects (38.6%), of whom 52 (85.2%) received a subsequent dose. With initial vaccination, the use of epinephrine was higher in subjects with LPhS (20%) compared to those without (6%; P = .0094). Fifty-two subjects (85.2%) with LPhS received a subsequent COVID-19 vaccine dose with milder or no symptoms, and none needed treatment with epinephrine. Those with LPhS were more likely to have a history of drug allergies (P = .02), severe medication allergies (P = .03), gastroesophageal reflux disease (P = .018), and need for antireflux medications (P = .0085) compared to controls.

Conclusions

In our registry, postvaccination LPhS were common. LPhS can mimic anaphylaxis and lead to more frequent use of epinephrine. Gastroesophageal reflux disease was more frequent in these subjects. Patients with subjective throat closure sensation can safely receive subsequent vaccine doses with close observation and reassurance. LPhS are not unique to COVID-19 vaccines. Patient and provider education regarding the role of gastroesophageal reflux disease as a risk factor for LPhS with vaccination can improve vaccine uptake.

Anaphylaxis: A 2023 practice parameter update

This practice parameter update focuses on 7 areas in which there are new evidence and new recommendations. Diagnostic criteria for anaphylaxis have been revised, and patterns of anaphylaxis are defined. Measurement of serum tryptase is important for diagnosis of anaphylaxis and to identify underlying mast cell disorders. In infants and toddlers, age-specific symptoms may differ from older children and adults, patient age is not correlated with reaction severity, and anaphylaxis is unlikely to be the initial reaction to an allergen on first exposure. Different community settings for anaphylaxis require specific measures for prevention and treatment of anaphylaxis. Optimal prescribing and use of epinephrine autoinjector devices require specific counseling and training of patients and caregivers, including when and how to administer the epinephrine autoinjector and whether and when to call 911. If epinephrine is used promptly, immediate activation of emergency medical services may not be required if the patient experiences a prompt, complete, and durable response. For most medical indications, the risk of stopping or changing beta-blocker or angiotensin-converting enzyme inhibitor medication may exceed the risk of more severe anaphylaxis if the medication is continued, especially in patients with insect sting anaphylaxis. Evaluation for mastocytosis, including a bone marrow biopsy, should be considered for adult patients with severe insect sting anaphylaxis or recurrent idiopathic anaphylaxis. After perioperative anaphylaxis, repeat anesthesia may proceed in the context of shared decision-making and based on the history and results of diagnostic evaluation with skin tests or in vitro tests when available, and supervised challenge when necessary.

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.

Use of adrenaline to manage suspected anaphylaxis following COVID-19 vaccination: An Australian retrospective cohort study

BACKGROUND

The rate of anaphylaxis following COVID-19 vaccinations is estimated to be 2-11 cases per million doses administered. However, adrenaline is occasionally used in individuals who are later diagnosed with immunisation stress-related responses, as their initial presenting signs and symptoms can appear similar to that of anaphylaxis. This study aims to describe the clinical profile of individuals who had received adrenaline following a COVID-19 vaccine and their subsequent revaccination outcomes.

METHODS

We examined notifications of cases who had received adrenaline following a COVID-19 vaccine in New South Wales, Australia. The cases were classified into Brighton Collaboration Case Definition (BCCD) for anaphylaxis, their clinical presentation, management and subsequent revaccination outcomes were compared.

RESULTS

From 22 February 2021 to 30 September 2021, there were 222 cases where adrenaline was administered. Of these, 32 (14 %) fulfilled Level 1 BCCD, 59 (27%) Level 2, 2 (1%) Level 3, 97 (44%) Level 4 and 32 (14 %) Level 5. The most commonly reported symptoms were sensation of throat closure (n = 116, 52%), difficulty breathing (n = 82, 37%) and nausea (n = 55, 25 %). Of the 176 (79%) individuals who proceeded to further vaccination, 89 (51%) received the same vaccine formulation and only 14 (8%) experienced another allergic adverse event with 9 (5%) receiving adrenaline.

CONCLUSION

Less than one in five individuals who received adrenaline met Level 1 BCCD criteria for anaphylaxis. Many reactions that were treated with adrenaline had little to no diagnostic certainty of anaphylaxis and in such cases repeat vaccination had a high likelihood of being tolerated. Increased awareness and education on objective signs and symptoms of anaphylaxis is required to ensure appropriate use of adrenaline.

How to define severity: A review of allergic reaction severity scoring systems

Numerous scoring systems have been developed to improve and standardize the diagnosis and management of acute allergic reactions and anaphylaxis; however, considerable variability exists among these systems. This review article discusses existing severity scoring systems and identifies specific knowledge gaps that remain. Future research is needed to resolve the limitations of existing grading systems, including attempting to link reaction severity with treatment advice and conducting validation studies in different clinical settings, patient populations, and geographies to promote grading system application and dissemination in both clinical care and research.

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.

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.