Updated Guidance Regarding The Risk ofAllergic Reactions to COVID-19 Vaccines and Recommended Evaluation and Management: A GRADE Assessment, and International Consensus Approach.

This guidance updates 2021 GRADE recomendations regarding immediate allergic reactions following COVID-19 vaccines and addresses re-vaccinating individuals with 1st dose allergic reactions and allergy testing to determine re-vaccination outcomes. Recent meta-analyses assessed the incidence of severe allergic reactions to initial COVID-19 vaccination, risk of mRNA-COVID-19 re-vaccination 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 recommenations. 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 UK, and the US formed the recommendations. We recommend vaccination for persons without COVID-19 vaccine excipient allergy, and re-vaccination after a prior immediate allergic reaction. We suggest against >15-minute post-vaccination observation. We recommend against mRNA vaccine or excipient skin testing to predict outcomes. We suggest re-vaccination 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 pre-medication, split-dosing, or special precautions because of a comorbid allergic history.

Type I Kounis syndrome induced by COVID-19 vaccination in China: a case report.

BACKGROUND: Kounis syndrome is a rare clinical condition characterized by the occurrence of an acute coronary event induced by an acute allergic episode. The ongoing pandemic of coronavirus disease 2019 (COVID-19) has contributed to an increase in the incidence of allergic reactions to a certain extent, thereby increasing the incidence of Kounis syndrome. Timely diagnosis and effective management of this disease are important in clinical practice. CASE PRESENTATION: We report a 43-year-old woman who developed generalized pruritus, breathlessness, paroxysmal precordial crushing pain, and dyspnea after receiving the third dose of the COVID-19 vaccine. After anti-allergic treatment and therapy for acute myocardial ischemia, her symptoms resolved with improvement in cardiac function and resolution of ST-segment changes. The prognosis was satisfactory, and the final diagnosis was type I Kounis syndrome. CONCLUSION: This patient with type I Kounis syndrome rapidly developed acute coronary syndrome (ACS) after an acute allergic reaction to the COVID-19 vaccine. ​Timely diagnosis of acute allergic reaction and ACS, and targeted treatment based on the relevant guidelines are the key to successful treatment of the syndrome.​.

COVID-19 Vaccines Are Safely Tolerated in Adolescents with Cutaneous Mastocytosis.

INTRODUCTION: The management of the COVID-19 vaccine in children with mastocytosis is unclear due to a lack of data. In the current study, we aimed to evaluate the adverse reactions following COVID-19 vaccination in adolescents with cutaneous mastocytosis (CM). METHODS: This study included 27 paediatric patients who were diagnosed with CM and were followed up in the paediatric allergy department of a tertiary care children's hospital. RESULTS: The median (IQR) age of the patients at the time of COVID-19 vaccination was 180 (156-203) months. Forty-four per cent of patients were vaccinated with the COVID-19 vaccine. Among all participants, the vaccination rate was found to be higher in older children, those who had been diagnosed with MPCM, and those who had not been infected with COVID-19 (p = 0.019, p = 0.009, p = 0.002, respectively). A total of 23 doses of the COVID-19 vaccine, including two doses of Sinovac/CoronaVac and 21 doses of Pfizer/BioNTech, were administered to 12 paediatric patients with CM. One of the patients had a history of intense itch, erythematous urticarial plaques, and had an exacerbation of existing skin lesions within 24-48 h after both doses of Pfizer/BioNTech vaccination. CONCLUSION: The COVID-19 vaccination of patients with CM in this series seems to be safe, and the rate of adverse events was comparable to that in the general population. These results found in adolescents with CM are in line with the existing evidence that CM does not preclude vaccination in children.

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.

Diagnostic accuracy of vaccine and vaccine excipient testing in the setting of allergic reactions to COVID-19 vaccines: A systematic review and meta-analysis.

For persons with immediate allergic reactions to mRNA COVID-19 vaccines, skin testing (ST) to the vaccine/excipients (polyethylene glycol[PEG] and polysorbate 80 [PS]) has been recommended, but has unknown accuracy. To assess vaccine/excipient ST accuracy in predicting all-severity immediate allergic reactions upon re-vaccination, systematic review was performed searching Medline, EMBASE, Web of Science, and the WHO global coronavirus database (inception-Oct 4, 2021) for studies addressing immediate (≤4 h post-vaccination) all-severity allergic reactions to 2nd mRNA COVID-19 vaccination in persons with 1st dose immediate allergic reactions. Cases evaluating delayed reactions, change of vaccine platform, or revaccination without vaccine/excipient ST were excluded. Meta-analysis of diagnostic testing accuracy was performed using Bayesian methods. The GRADE approach evaluated certainty of the evidence, and QUADAS-2 assessed risk of bias. Among 20 studies of mRNA COVID-19 first dose vaccine reactions, 317 individuals underwent 578 ST to any one or combination of vaccine, PEG, or PS, and were re-vaccinated with the same vaccine. Test sensitivity for either mRNA vaccine was 0.2 (95%CrI 0.01-0.52) and specificity 0.97 (95%CrI 0.9-1). PEG test sensitivity was 0.02 (95%CrI 0.00-0.07) and specificity 0.99 (95%CrI 0.96-1). PS test sensitivity was 0.03 (95%CrI 0.00-0.0.11) and specificity 0.97 (95%CrI 0.91-1). Combined for use of any of the 3 testing agents, sensitivity was 0.03 (95%CrI 0.00-0.08) and specificity was 0.98 (95%CrI 0.95-1.00). Certainty of evidence was moderate. ST has low sensitivity but high specificity in predicting all-severity repeat immediate allergic reactions to the same agent, among persons with 1st dose immediate allergic reactions to mRNA COVID-19 vaccines. mRNA COVID-19 vaccine or excipient ST has limited risk assessment utility.

Non-clinical safety evaluation of prophylactic mRNA vaccine:general principles and concerns

Messenger RNA（mRNA） vaccine, with antigen-encoded mRNA packaged in delivery vehicles, performs its functions via antigen translation and specific immune response. mRNA vaccines have proven their protective effects and safety in the ongoing COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2（SARS-CoV-2）. The World Health Organization issued guidelines specifically for prophylactic mRNA vaccines in 2021, which provide important guidance for non-clinical research on mRNA vaccines. Furthermore, some unusual adverse reactions, such as cerebrovascular disease, embolic stroke, transient cerebral ischemia, deep vein thrombosis, myocarditis（pericarditis） and allergic reactions, have been also found in clinical trials and applications of mRNA vaccines, which deserves attention in non-clinical studies.

Prevalence and Risk Factors of Adverse Effects and Allergic Reactions after COVID-19 Vaccines in a Mexican Population: An Analytical Cross-Sectional Study.

Vaccinations have helped to control the COVID-19 pandemic; however, few studies focus on the adverse effects and allergic reactions of these vaccines and fewer have a scope in the Latin American population. The objective of this study was to assess the associations between vaccinations, sex, age, allergic reactions, and adverse effects. This was an analytical cross-sectional study conducted between 1 July and 1 October 2022. The sample consisted of 443 surveyed participants, with a total of 1272 COVID-19 vaccine doses. Seven vaccines (Pfizer BioNTech, Oxford-AstraZeneca, CanSino, Moderna, Johnson and Johnson, Sinovac, and Sputnik V) were evaluated. A total of 12.6% of those surveyed had at least one allergic reaction posterior to vaccination, and females had a greater chance of developing one (p < 0.001, OR 3.1). The most common allergic reaction was chest pain, and Pfizer-BioNTech and Oxford-AstraZeneca were associated with the onset of allergic reactions (p < 0.005). A total of 54.6% of those surveyed developed adverse effects, the most common of which were myalgia, fever, cephalea, asthenia or adynamia, and arthralgia; moreover, older age was associated with the onset of adverse effects (p < 0.5). This study concludes that the BNT162b2 (Pfizer BioNTech) and ChAdOX1 nCOV-19 (Oxford-AstraZeneca) vaccines are strongly associated with the onset of allergic reactions, with ORs of 1.6 (CI 95%, 1.18 to 2.3) and 1.87 (CI 95%, 1.35 to 2.6), respectively. In addition, females have a greater chance of developing allergic reactions associated with COVID-19 vaccinations, and there was a relation found between older age and a greater prevalence of comorbidities, adverse effects after vaccination, and COVID-19 infection after vaccination.

Anaphylaxis is rare due to CoronaVac in a population of healthcare workers.

Background: CoronaVac, the first coronavirus disease 2019 vaccine administered in our country, was found safe in clinical trials. Objective: We aimed to reveal the rate and features of CoronaVac vaccine-associated allergic reactions among vaccinated healthcare workers (HCWs) in real-life. Methods: This study was planned as a questionnaire-based study. Participants who reported a postvaccination allergic reaction were interviewed on phone and their medical records were also checked for confirmation. Results: A total of 2,488 HCWs took part in the study and 4,054 postvaccination complete questionnaire-responses were obtained. Twenty-one HCWs (female: male, 17:4) with a mean age of 40.95 ± 10.09 stated that they had an allergic reaction after a total of 23 vaccine injections. Accordingly, the reaction rate was 0.56% among all vaccine doses. The most common reactions were systemic skin reactions (2.7%) consisting of generalized pruritus, diffuse pruritic erythema, urticaria, and maculopapular rash. That was followed by local injection site reaction (0.12%). Anaphylaxis was reported in 4 cases (0.09%) with a mean onset time of 12 ± 6 minutes. One of them had a history of anaphylaxis with 2 drugs, another had venom and food allergy. Three of the subjects had level 2 diagnostic certainty according to the Brighton Collaboration criteria and one had level 3. All anaphylaxis cases were discharged within 24 hours and none of them required intensive care. Conclusion: Our study demonstrated that allergic reactions to CoronaVac were rare and mostly mild. Although anaphylaxis was also rare, the importance of early intervention with close follow-up was once again emphasized.

Multi-perspective Characterization of Anaphylactic Risk for COVID-19 Vaccination - A Visual Analytic Approach

Currently, communications of the COVID-19 vaccine risk and benefit have been confusing and ineffective. This research presents a visual analytical approach to enable decision-driven, multi-perspective risk characterization of COVID-19 vaccination. Using data collected from Vaccine Adverse Event Reporting System (VAERS), we designed multiple-views dash-boards based on identified risk factors to support interactive explorations of anaphylactic risks from policy, clinical, and personal contexts. Based on the hypothetical scenarios, we showed that our visual analytical approach offers multiple benefits for risk characterization tasks, including flexibility in focusing on the subset of risk factors that are specific to user's decision context, exploring and assessing risk in multiple levels of details, and characterizing risk metrics together with uncertainties. Our method and tools have potentials of improving COVID-19 vaccine risk communication to address vaccine hesitancy and to inform public policy. © 2022 IEEE.

Urticaria Reactions after COVID-19 Vaccination: A Case Series: An International Journal of Medical Toxicology and Drug Experience

Introduction: COVID 19 vaccines are considered as an important medical advance in healthcare. It is the most promising approach for curbing the COVID-19 pandemic. However, as the number of people receiving vaccination rises, we are inevitably faced with increasing adverse drug reactions. The most common adverse reactions to vaccines are non-allergic, as flu like-symptoms and injection site reactions. Immediate hypersensitivity reactions are fortunately rare [1,2]. Objective: The aim of our work was to study clinical characteristics of acute urticaria following COVID-19 vaccines reported to the Tunisian National Center of Pharmacovigilance. Methods: We conducted a retrospective study involving all cases of acute urticaria related to COVID-19 vaccines since the onset of the vaccine campaign in March 2021 to May 2022. Results: This study included 70 patients. Age ranged from 15 to 77 years old with a median age of 26 years. There were 51 women, and the sex ratio M/F was 0.37. The onset of urticaria varied from few hours to 17 days following vaccine injection with an average delay of 4 days. In 56 cases, urticaria occurred following 1st shot, in 10 cases following the 2nd dose and one case was reported following the 3rd dose of vaccine. This data was not mentioned in 3 cases. Outcome was favorable in 57 cases and unknown in 13 cases. Involved vaccines were Pfizer/BioNTech (47.14%), SPIKEVAX COVID-19 Vaccine Moderna (20%), AstraZeneca COVID-19 vaccine (15.71%), COVID-19 Vaccine Janssen (11.42%), CORONAVAC SINOVAC COVID-19 VACCINE (2.85%) and Sputnik V (2.85%). Urticaria was isolated in 58 cases, was associated with angioedema in 7 cases, and with fever in 5 cases. Conclusion: Our work showed a very low number of cases of acute urticaria following Covid-19 immunization. The Center for Disease Control and Prevention recommend, in patients who had even within 4 hours of getting vaccinated a non-severe allergic reaction to COVID-19 Vaccine to receive another dose of the same vaccine under medical surveillance. This is suggesting a non-specific mechanism.

Impacts of Air Pollution and Dampness on Occupant Respiratory Health in Unplanned Houses: A Case Study of Bandung, Indonesia

This paper presents the results from field measurements and household surveys on the severity of indoor mold risk and its impact on respiratory health in a typical unplanned neighborhood of kampungs in Bandung, Indonesia. Mold risk was investigated using fungal risk detectors (n = 102), while air pollution levels were established with total suspended particulate (TSP) and particulate matter (PM2.5) (n = 38). The self-reported prevalence of respiratory diseases was obtained using a questionnaire form (ATS-DLD-78) (n = 599). The results showed that respiratory health problems were higher in the rainy season, particularly among children. Most houses suffered from severe mold risk, primarily due to extreme humid weather conditions, especially during rainy season (97%) where water leakage was prevalent (60%). In addition, the TSP and PM2.5 concentrations exceeded the WHO standards in most kampung houses, where around 58% of the houses recorded higher outdoor mean PM2.5 concentrations than indoors. Further, the path analysis showed that allergies followed by humidity rate and smell, which were affected by window-opening duration, directly impacted children’s respiratory health. Smoking behavior and building-related health problems, due to exposure to outdoor air pollution, affected the respiratory health of those aged 15 years old and over.

The effect of the vaccine against viral pneumoenteritis left-pointing-double-angle Bolshevak right-pointing-double-angle on the metabolism of cows

The problem of viral pneumoenteritis of young farm animals is relevant for agriculture of the Republic of Belarus. Today, the most effective method of preventing viral pneumoenteritis of calves is vaccination of pregnant cows. In case of mixed infections, the most effective means of preventing such diseases are polyvalent vaccines. But biological preparations should have not only high preventive effectiveness, but also not affect the quality of the final product. The author of the article studied the effect of a polyvalent inactivated culture vaccine against infectious rhinotracheitis, viral diarrhea, parainfluenza-3, respiratory syncytial, rotavirus and coronavirus infection of cattle left-pointing-double-angle BolsheVak right-pointing-double-angle on the state of metabolism of pregnant cows. For this purpose, 3 groups of pregnant cows of the Belarusian black-and-white Holstein breed were formed in the conditions of the Agricultural Republican subsidiary of the Ulishitsy Agro enterprise of the Gorodok district on the principle of pairs of analogues with10 animals in each group for 1.5-2 months before calving. The cows of the first experimental group were immunized with the vaccine against viral pneumoenteritis "Bolshevak" with the adjuvant ISA-15 intramuscularly into the croup area in compliance with the rules of asepsis and antiseptics in the volume of 5.0 cm3. Cows of the second experimental group were immunized with the vaccine against viral pneumoenteritis "Bolshevak" with the adjuvant ISA-25 - in the volume of 3.0 cm3. The cows of the control group were injected with isotonic sodium chloride solution according to a similar scheme. The animals were immunized twice with an interval of 21 days. The sampling was carried out before the start of the studies, on the 14th, 21st days after the first vaccination and on the 45th day after the revaccination. The clinical condition of the animals was monitored for 70 days. As a result of the research, it was found that the studied vaccine against viral pneumoenteritis does not have a negative effect on the general condition of the animal, does not cause allergic reactions, abortions, does not inhibit the synthesis of the studied biochemical parameters of the serum.

Safety of an inactivated COVID-19 vaccine in patients with - wheat-dependent exercise-induced anaphylaxis.

BACKGROUND: Inactivated vaccines against coronavirus disease-2019 (COVID-19) offer an effective public health intervention to mitigate this devastating pandemic. However, little is known about their safety in patients with wheat-dependent exercise-induced anaphylaxis (WDEIA). METHODS: We recruited 72 WDEIA patients and 730 healthy matched controls who received an inactivated COVID-19 vaccine. Participants were monitored for 4 weeks after each immunization for adverse reactions and completed questionnaires regarding local and systemic reactions at 7 and 28 days after each vaccination. For those who had received the COVID-19 vaccine prior to enrollment, adverse event data were obtained retrospectively. RESULTS: Local and systemic adverse events occurred at similar rates in the WDEIA group and the control group. In both groups, injection-site pain and fatigue were the most common local and systemic reactions, respectively. Compared with healthy controls, more allergic events were reported in the WDEIA group (after dose 1, 0.5% vs. 4.2%, p=0.019; after dose 2, 0% vs. 1.4%, p=0.089). Allergic reactions mainly manifested as rash, urticaria, and edema, which were mild and controllable. No serious allergic events were reported. CONCLUSIONS: The adverse event profile of inactivated COVID-19 vaccine did not differ between WDEIA patients and healthy controls. The risk of allergic reactions in patients with WDEIA seems higher, but no anaphylaxis was reported, and the allergic reactions were controllable. Inactivated COVID-19 vaccines appear to be well-tolerated in WDEIA patients, but patients with potential allergy risks should be cautious.

Risk, causality and management of severe allergic reactions of RNA messenger SARS-CoV-2 vaccine: a mini review

SARS-CoV-2 infection has become a health problem throughout the world, including Indonesia with high rates of morbidity (more than 3 million confirmed case) and mortality (more than 80 thousand) due to COVID-19 since it was announced as pandemic in March 2020. Vaccination is one of the efforts to eliminate the pandemic, and just recently Food and Drug Monitoring Agency (BPOM) and Indonesian Government have granted approval for emergency use of messenger RNA (mRNA)-based vaccines. Allergic reactions after vaccination are rare adverse events, including severe allergic reactions and anaphylaxis. Polyethylene glycol (PEG) in mRNA vaccines is thought to be a hidden allergen that trigger allergies. Screening of individuals with a previous history of allergies is necessary to prevent reaction. Experienced health workers are also needed to provide adequate management in the event of a severe allergic reaction or anaphylaxis after COVID-19 vaccination. Aim of this review is to look at the risk of allergy of mRNA vaccine SARS CoV-2;possible causes of allergies and management of individuals with severe allergies/anaphylaxis.

Comparison of Covishield versus Covaxin in COVID-19 pandemic

Background: Viral diseases continue to emerge and represent a serious issue to public health. The present study compared Covishield versus Covaxin in COVID- 19 pandemic.

Self-reported reactogenicity of CoronaVac (Sinovac) compared with Comirnaty (Pfizer-BioNTech): A prospective cohort study with intensive monitoring.

OBJECTIVE: CoronaVac (Sinovac) Covid-19 vaccine has recently been approved for emergency use by the World Health Organization. However, data on its reactogenicity in real-world settings is scant. This study aimed to compare self-reported post-vaccination adverse reactions between CoronaVac and Comirnaty (Pfizer-BioNTech). METHODS: We adopted a prospective cohort study design using online surveys from the day of first-dose vaccination with intensive follow-up through two weeks after the second dose (11 time points). The primary outcome was adverse reactions (any versus none) and secondary outcomes were the sub-categories of adverse reactions (local, systemic, and severe allergic reactions). Potential effect modification across multimorbidity status, older age, and sex was examined. RESULTS: In total, 2,098 participants who were scheduled to complete the 14th-day survey were included, with 46.2% receiving Comirnaty. Retention rate two weeks after the second dose was 81.0% for the CoronaVac group and 83.6% for the Comirnaty group. Throughout the follow-up period, 801 (82.7%) of those receiving Comirnaty and 543 (48.1%) of those receiving CoronaVac reported adverse reactions. Adjusted analysis suggested that compared with Comirnaty, CoronaVac was associated with 83%-reduced odds of any adverse reactions [adjusted odds ratio (AOR) = 0.17, 95% confidence interval (CI) 0.15-0.20], 92%-reduced odds of local adverse reactions (AOR = 0.08, 95% CI 0.06-0.09), and 76%-reduced odds of systemic adverse reactions (AOR = 0.24, 95% CI 0.16-0.28). No significant effect modification was identified. CONCLUSION: This post-marketing study comparing the reactogenicity of Covid-19 vaccines suggests a lower risk of self-reported adverse reactions following vaccination with CoronaVac compared with Comirnaty.

An Analysis of Covid-19 Vaccine Allergic Reactions

From our study, all three covid-19 vaccines have a similar proportion of adverse reaction reports in which the patient had a history of allergies. However, the proportion of life-threatening outcomes were lower for those with the Janssen vaccine (0.62% hospitalization rate for Janssen versus 2.59% for Pfizer and 0.60% death for Janssen versus 5.15% for Moderna). In terms of specific allergies, patients with ·cillin or sulfa allergies had the most adverse reactions to covid-19 vaccines, however, Janssen again had the lowest percentage of reported deaths (1.39% for ·cillin-related allergy deaths for Janssen versus 6.10% for Pfizer). In terms ofpatient age and gender, females has 2.9x the number of adverse reactions than males and a lower average age for reactions for the Pfizer and Moderna vaccines. We feel this data could be used by individuals and medical professionals to assist in choosing a vaccine to maximize patient safety based on their allergy history, age and gender.

Cutaneous and Allergic reactions due to COVID-19 vaccinations: A review.

INTRODUCTION: The pandemic caused by the novel coronavirus disease 2019 (COVID-19) has had an unprecedented impact on the overall health and the global economy. Vaccination is currently the most dependable strategy to end the pandemic, despite the slower-than-hoped-for rollout, particularly for low-to-middle-income countries, and the uncertain duration of protection afforded by vaccination. The spike protein of the virus (immunodominant antigen of the virus) is the main target of the approved and candidate SARS-CoV-2 vaccines. This protein binds to the ACE2 receptor of the host cell, initiating the entry of the virus into the cell and the chain of subsequent events ending to Acute Respiratory Distress Syndrome. The safety profile of these vaccines needs is closely assessed. METHODS: This comprehensive review includes searching the PubMed, EMBASE, and Web of Science databases using the keywords "coronavirus", "COVID-19", "vaccine", "cutaneous reactions", "allergic reactions", and "SARS-CoV-2". Manual searching of reference lists of included articles augmented the research. The research was updated in June 2021. RESULTS: In this narrative review, we tried to investigate and discuss the cutaneous and allergic reactions related to SARS-CoV-2 vaccines currently available in the literature. As a result, although COVID-19 vaccines can be reported to develop allergic and anaphylactic reactions, especially after m-RNA vaccines, they remain at a low rate, and it is observed that these reactions may develop more frequently, especially in patients with previous allergies and mast cell disorders. Fortunately, these reactions are generally transient, benign, self-limited. CONCLUSION: Although there is still no definitive evidence, as dermatologists, we must be aware of the possibility of cutaneous reactions, newly diagnosed dermatoses, or exacerbation of existing dermatoses that may develop after the COVID-19 vaccinations.

The value of the basophil activation test in the evaluation of patients reporting allergic reactions to the BNT162b2 mRNA COVID-19 vaccine.

BACKGROUND: mRNA-based COVID-19 vaccines have been reported to induce hypersensitivity reactions (HSR) in a small number of individuals. We aimed to evaluate the real-world incidence of the BNT162b2 mRNA COVID-19 vaccine HSR and to determine the value of the basophil activation test (BAT) in the allergological workup of patients reporting these reactions. METHODS: We prospectively enrolled patients with a clinical history indicative of HSR to the BNT162b2 mRNA COVID-19 vaccine. The allergological workup included skin testing (STs) and BAT with polyethylene glycol (PEG) and the vaccine. In those with negative allergy assessments, the administration of the second dose of the BNT162b2 mRNA COVID-19 vaccine was offered. RESULTS: Seventeen adults were included. Eleven cases (64.7%) tested negative in the allergological workup and tolerated the re-administration of the second dose of the vaccine and considered non-allergic. Six cases (35.3%) were considered allergic and classified into three groups: 2 subjects displayed positive STs and/or BAT to PEG (Group A), two individuals displayed positive BAT to the vaccine (Group B), and in 2 patients with moderate or severe reactions, the culprit was not identified, tested negative to STs and BAT to both PEG and vaccine (Group C). We further evaluated the value of BAT when the results were positive to the vaccine and negative to PEG by performing BAT in controls groups, finding positive BAT results in 50% of controls, all of them recovered from COVID-19 infection. In contrast, BAT was negative in patients who had not suffered from COVID-19 disease. CONCLUSIONS: BAT can be used as a potential diagnostic tool for confirming allergy to PEG excipient but not to the vaccine as a positive result in BAT may indicate a past COVID-19 infection instead of an allergy.

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.