Safety of COVID-19 vaccination in patients with clonal mast cell disorders

Latent Mastocytosis Triggered by COVID-19 Vaccination: A Case Report

BACKGROUND

Hereby, we describe the first case of latent mastocytosis triggered by mRNA-based vaccine to prevent COVID-19 infection.

CASE PRESENTATION

In a 42-year-old Arabian man affected by slight, undiagnosed mastocytosis, the second dose of the COVID-19 vaccine made more blatant his latent disease. The postvaccination diagnostic iter is illustrated and the potential reasons causing the onset of the cutaneous mastocytosis are discussed.

CONCLUSION

Clinicians should keep a longer follow-up of their patients after the COVID-19 vaccination, not related to few hours, for the risk of immediate-type adverse events only.

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.

The conundrum of COVID-19 mRNA vaccine-induced anaphylaxis

Novel messenger RNA (mRNA) vaccines have proven to be effective tools against coronavirus disease 2019, and they have changed the course of the pandemic. However, early reports of mRNA vaccine-induced anaphylaxis resulted in public alarm, contributing toward vaccine hesitancy. Although initial reports were concerning for an unusually high rate of anaphylaxis to the mRNA vaccines, the true incidence is likely comparable with other vaccines. These reactions occurred predominantly in young to middle-aged females, and many had a history of allergies. Although initially thought to be triggered by polyethylene glycol (PEG), lack of reproducibility of these reactions with subsequent dosing and absent PEG sensitization point away from an IgE-mediated PEG allergy in most. PEG skin testing has poor posttest probability and should be reserved for evaluating non-vaccine-related PEG allergy without influencing decisions for subsequent mRNA vaccination. Immunization stress-related response can closely mimic vaccine-induced anaphylaxis and warrants consideration as a potential etiology. Current evidence suggests that many individuals who developed anaphylaxis to the first dose of an mRNA vaccine can likely receive a subsequent dose after careful evaluation. The need to understand these reactions mechanistically remains critical because the mRNA platform is rapidly finding its way into other vaccinations and therapeutics.

Anaphylaxis: Advances in the Past 10 Years

In the past 10 years, anaphylaxis has grown into its own special area of study within Allergy-Immunology, both at the bench and at the bedside. This review focuses on some of the most clinically relevant advances over the past decade. These include simplified and more inclusive diagnostic criteria for adults and children, uniform definition of biphasic anaphylaxis, and improved systems for objective severity grading. Studies reported in the past decade have led to improved understanding of normal and abnormal regulation of mast cell function, translating into better diagnostic and therapeutic approaches to patients with anaphylaxis. Research has provided improved recognition and treatment of mast cell disorders and has identified a new condition, hereditary α-tryptasemia, that may impact anaphylactic syndromes. We have learned to recognize new causes (α-gal), new pathways (Mas-related G protein-coupled receptor-X2), and many risk factors for severe anaphylaxis. The stability of epinephrine in autoinjectors was reported to be very good for several years after the labeled expiry date, and it can tolerate freezing and thawing. Repeated and prolonged exposure to excessive heat leads to degradation of epinephrine activity. New treatments to prevent severe anaphylaxis have been described, using new ways to block the IgE receptor or modulate intracellular signaling pathways.

Attitudes and Beliefs of the Italian Population towards COVID-19 Vaccinations

Background: Despite the numerous campaigns to encourage vaccination against COVID-19, the public debate and often conflicting information have left many individuals uncertain about the decision to make on whether or not to vaccinate. Methods: This research aims to analyze the attitudes and beliefs of the Italian population towards COVID-19 and other vaccinations through a quantitative methodology. In all, 500 adults (Age M = 39.52) participated in this exploratory study with an online questionnaire conducted in April 2021. Results: most participants believe vaccination is necessary to defeat COVID-19; there is an age-related difference in getting vaccinations, and women were more afraid of unexpected future effects than men; older participants have expressed a greater willingness to pay to be vaccinated against COVID-19 (4). Conclusion: In light of these results, it is necessary to pay greater attention to the perplexity and fears expressed by the population, especially women and youth, in relation to vaccinations; in fact, it would help to achieve a wider adherence to the tools designed to contain the spread of viruses at the base of severe health crises.

COVID-19 Vaccination Is Safe among Mast Cell Disorder Patients, under Adequate Premedication

Reported cases of anaphylaxis following COVID-19 vaccination raised concerns about the safety of these vaccines, namely in patients suffering from clonal mast cell (MC) disorders-a heterogenous group of disorders in which patients may be prone to anaphylaxis caused by vaccination. This study aimed to assess the safety of COVID-19 vaccines in patients with clonal MC disorders. We performed an ambidirectional cohort study with 30 clonal MC disorder patients (n = 26 in the prospective arm and n = 4 in the retrospective arm), that were submitted to COVID-19 vaccination. Among these, 11 (37%) were males, and median age at vaccination date was 41 years (range: 5y to 76y). One patient had prior history of anaphylaxis following vaccination. Those in the prospective arm received a premedication protocol including H1- and H2-antihistamines and montelukast, while those in the retrospective arm did not premedicate. Overall, patients received a total of 81 doses, 73 under premedication and 8 without premedication. No MC activation symptoms were reported. COVID-19 vaccination seems to be safe in patients with clonal mast cell disorders, including those with prior anaphylaxis following vaccination. Robust premedication protocols may allow for vaccination in ambulatory settings.