Intradermal Testing With COVID-19 mRNA Vaccines Predicts Tolerance

Chronic Spontaneous Urticaria Following mRNA COVID-19 Booster Vaccination at a Military Academy

Several adverse cutaneous reactions have been reported in the literature after SARS-CoV-2 vaccination with emerging reports on chronic spontaneous urticaria (CSU). However, there is little literature of chronic urticaria after COVID-19 boosters in a military population and the impact on operational readiness. We present a retrospective case series of CSU following Moderna COVID-19 booster vaccinations at the US Naval Academy (USNA). Demographics, clinical features, and impact on readiness were evaluated. Forty-nine students from the USNA were evaluated for urticaria after their third COVID-19 booster vaccination. Seventeen individuals were diagnosed with CSU. The median age was 20 years and predominantly male; the median time interval between vaccination and the onset of urticaria was 11 days. Out of 13 referred to Allergy, 7 patients had CU index performed and 2 were positive. Four patients received a second booster vaccination subsequently and did not have any exacerbation of symptoms. Symptoms were controlled with antihistamines, and none required immunomodulator or immunosuppressive therapies. All students were able to complete their commissioning, and none were referred for a medical board. In this series, USNA students who developed CSU after the mRNA COVID-19 Moderna booster vaccine did not have limitations from commissioning, duty status, or issues with subsequent COVID-19 vaccinations.

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.

Intradermal skin test with mRNA vaccines as a surrogate marker of T cell immunity in immunocompromised patients

OBJECTIVES

Intradermal skin test (IDT) with mRNA vaccines may represent a simple, reliable, and affordable tool to measure T cell response in immunocompromised patients who failed to mount serological responses following vaccination with mRNA covid-19 vaccines.

METHODS

We compared anti-SARS-CoV-2 antibodies and cellular responses in vaccinated immunocompromised patients (n=58), healthy seronegative naive controls (NC, n=8), and healthy seropositive vaccinated controls (VC, n=32) by Luminex, spike-induced IFN-γ Elispot and an IDT. A skin biopsy 24h after IDT and single-cell RNAseq was performed in three vaccinated volunteers.

RESULTS

Twenty-five percent of seronegative NC had a positive Elispot (2/8) and IDT (1/4), compared to 95% (20/21) and 93% (28/30) in seropositive VC, respectively. Single-cell RNAseq data in the skin of VC showed a predominant mixed population of effector helper and cytotoxic T cells. The TCR repertoire revealed 18/1064 clonotypes with known specificities against SARS-CoV-2, among which six were spike-specific. Seronegative immunocompromised patients with positive Elispot and IDT were in 83% (5/6) treated with B cell-depleting reagents, while those with negative IDT were all transplant recipients.

CONCLUSIONS

Our results indicate that delayed local reaction to IDT reflects vaccine-induced T-cell immunity opening new perspectives to monitor seronegative patients and elderly populations with waning immunity.

Incidence of Chronic Spontaneous Urticaria Following Receipt of the COVID-19 Vaccine Booster in Switzerland

This cohort study examines the association of the COVID-19 vaccine booster with chronic spontaneous urticaria in Swiss patients.