Incidence of immediate allergic reactions to mRNA COVID-19 vaccines in adults with drug allergies and other allergic disorders

Drug-induced hypersensitivity reactions in a Lebanese outpatient population: A decade-long retrospective analysis (2012-2021)

Background

Drug hypersensitivity reactions (DHRs) are becoming more common as a result of increasing prevalence and case complexity. Allergists and clinical immunologists worldwide are challenged daily to adequately diagnose and manage these reactions. Data in the literature regarding DHR outpatient consultations are scarce worldwide, limited in the Middle East, and currently unavailable in Lebanon.

Objective

This retrospective study aimed to evaluate the characteristics of all reported DHRs over 10 years in a tertiary-care allergy clinic in Lebanon.

Methods

We conducted a decade-long (2012-21) retrospective analysis of the archived medical records of patients with a history of DHRs. Demographics, clinical history, diagnostic tools, and characteristics of the DHRs were collected and analyzed.

Results

A total of 758 patients experienced DHRs to therapeutic molecules provided for ambulatory care. Our results identified 72 medications. The most frequently implicated drug classes included β-lactam antibiotics (53.8%), followed closely by nonsteroidal anti-inflammatory drugs (48.9%). Of the 758 patients, 32.6% reported DHRs to multiple molecules, and 11.8% reported concomitant DHRs to 1 or several molecules provided in the perioperative setting. Of those, opioids and neuromuscular blocking agents were the 2 most common therapeutic classes. Furthermore, we evaluated the cross-reactivity between molecules of the same class. In neuromuscular blocking agents, rocuronium and cisatracurium were the most commonly cross-reactive, and for opioids, the most common association we recorded was with morphine and pethidine.

Conclusion

Our findings constitute the first step toward a more comprehensive evaluation of the clinical characteristics of DHRs in Lebanon.

The usability of testing skin reaction applying skin prick tests with Comirnaty (Pfizer, USA) vaccine in detecting the risk of developing post-vaccination immediate hypersensitivity response (anaphylaxis) after administration of this vaccine

Introduction

COVID-19 vaccines became a relevant element of prevention during COVID-19 pandemic. It is worth highlighting the importance of severe allergic post-vaccination reactions.

Aim

To evaluate the usability of skin reaction tests using skin prick tests with Comirnaty (Pfizer, USA) vaccine in risk detection of the post-vaccine immediate hypersensitivity reaction (anaphylaxis) after administration of this vaccine [PvIHR(A)].

Material and methods

The analysis embraces 102 people, 85 women and 17 men with a history of immediate hypersensitivity (anaphylaxis) [IHR(A)]. Detailed medical history was collected and skin prick tests were made among participants. The positive and negative test results were illustrated in Figure 1.

Results

As it stands in Table 1, considering all participants of the study, a positive result of the skin prick tests was obtained only in 2 cases, a negative result in 99 and 1 result was questionable. The two positive results were found in participants from a group with a previous PvIHR(A) in their past medical history and they decided not to get vaccinated. The one questionable result was of a person that had PvIHR(A) after administration of the first dose of Comirnaty vaccine (Pfizer, USA). This person decided to get vaccinated again and there was no PvIHR(A) observed.

Conclusions

COVID-19 vaccination involves a low risk of anaphylaxis. Purposefulness of providing the skin prick tests using the mRNA vaccine is questionable, due to their low sensitivity and low specificity.

mRNA vaccines for cancer immunotherapy

Immunotherapy has emerged as a breakthrough strategy in cancer treatment. mRNA vaccines are an attractive and powerful immunotherapeutic platform against cancer because of their high potency, specificity, versatility, rapid and large-scale development capability, low-cost manufacturing potential, and safety. Recent technological advances in mRNA vaccine design and delivery have accelerated mRNA cancer vaccines' development and clinical application. In this review, we present various cancer vaccine platforms with a focus on nucleic acid vaccines. We discuss rational design and optimization strategies for mRNA cancer vaccine development. We highlight the platforms available for delivery of the mRNA vaccines with a focus on lipid nanoparticles (LNPs) based delivery systems. Finally, we discuss the limitations of mRNA cancer vaccines and future challenges.