Successful SARS-CoV-2 vaccine allergy risk-management: The experience of a large Italian University Hospital

Abstract

BACKGROUND Novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccines have been recently approved, and public concern regarding the risk of anaphylactic reactions arised after few cases during the first days of mass-vaccination. Polyethylene glycol (PEG) has been suggested as the most probable culprit agent for allergic reactions. OBJECTIVE We describe the allergy work-up protocol implemented for the vaccination campaign in our Center, aiming to allow the greatest number of people to be vaccinated safely. METHODS the protocol included the self-report of a history of suspected drug or vaccine allergies, and subsequent teleconsultation and allergometric tests for PEG and Polysorbate 80 (PS80). A desensitizing protocol of vaccine administration was applied to patients sensitized only to PS80, and to those with a suspect allergic reaction after the first vaccine dose. RESULTS 10.2% (414 out of 4042) of the entire vaccine population have been screened: only one patient resulted allergic to PEG and therefore excluded from the vaccination. Another patient was sensitized to PS80 only and safely vaccinated applying the desensitizing protocol. Seven subjects without a previous history of allergic disease experienced suspect hypersensitivity reactions to the first administered dose: one of them resulted allergic to PEG and was excluded from the second dose, while the others safely completed the vaccination with the desensitizing protocol. CONCLUSION a careful allergological risk-assessment protocol significantly reduces the number of patients who would have avoided SARS-CoV-2 vaccination for their allergies and to effectively identify and manage those rare patients with sensitization to PEGs and/or PS80.

Cutaneous and hypersensitivity reactions associated with COVID-19 vaccination—a narrative review

“…Pre-vaccination screening for PEG sensitization has been performed by Paoletti et al (2021) and Banerji et al (2021) [28,29]. Paoletti et al (2021) screened about 10% of their whole vaccination population and detected a single person with a positive reaction to PEG to be excluded from vaccination.…”

“…Pre-vaccination screening for PEG sensitization has been performed by Paoletti et al (2021) and Banerji et al (2021) [28,29]. Paoletti et al (2021) screened about 10% of their whole vaccination population and detected a single person with a positive reaction to PEG to be excluded from vaccination. Although test protocols and substances used for testing are yet not standardized nor validated, they conclude that their screening helped to reduce anaphylactic reactions to mRNA vaccines [29].…”

A case series of cutaneous COVID-19 vaccine reactions at Loma Linda University Department of Dermatology

“…Topical exposure to products containing a PEG vehicle have been associated with immediate urticarial and delayed eczematous eruptions. [14][15][16][17] Paoletti et al 18 highlighted the PEG products in the Pfizer and Moderna vaccines as the most likely culprit ingredient resulting in anaphylactic reactions.…”

Challenges to Vaccination against SARS-CoV-2 in Patients with Immune-Mediated Diseases

“…With the caveat that skin tests to SARS-CoV-2 vaccines and their excipients are not standardised, data from three studies ( Supplementary Table S4 ) reporting in vivo data show that positive skin tests to polyethylene glycol or polysorbate-80 might have a prevalence of about 1% in cohorts of patients with physician-validated diagnosis of clinically relevant allergies. This percentage might rise to about 6% in patients with definite clinical suspicion of sensitisation to vaccine excipients [ 34 , 45 ] and to at least 14% in patients with no previous history of allergy and new-onset hypersensitivity to the first vaccine dose ( Supplementary Table S4 ). No patient has so far been reported with positive skin tests to one or more vaccines.…”

“…No patient has so far been reported with positive skin tests to one or more vaccines. Strikingly, of 226 patients who underwent a clinical/skin-test triage to confirm their fitness to safely receive anti-SARS-CoV-2 vaccination, only one (0.44%) had a mild immediate-type reaction at least after the first dose, possibly suggesting that these relatively simple approaches are feasible to apply in the normal clinical practice [ 41 , 45 ].…”