[Suspected allergy to COVID-19 vaccines: A retrospective study of 320 patients]

The health context with COVID-19 pandemic has led to fast development of many vaccines against the SarS-Cov-2 virus. Four of them are currently available in France and contain polyethylene glycol (PEG) or polysorbate 80 as excipients, already described as causing anaphylaxis. French recommendations have been suggested by allergology authorities and proposed a course of action in the event of a suspected allergy to these vaccines. Thus, allergies to excipients were the only contraindication to COVID-19 vaccination. Our main objective was to determine the impact of these allergology vaccine recommendations on the management of these patients. Our secondary objective was to determine prevalence of true allergies to these vaccines.

We conducted a unicentric descriptive retrospective study with all patients over 18 years of age referred for an allergological opinion before or after an injection of one of the anti-COVID-19 vaccines. Nineteen patients were classified into different interest groups, based on french recommendations.

The vast majority of patients did not require a pre-vaccination allergological assessment. Indeed, only 25 patients received skin tests prior to vaccination. The rest of patients were able to be vaccinated without allergological assessment. Patients not vaccinated due to allergy to excipients represent less than 1% of the population (n = 3/320).

French recommendations made it possible to vaccinate the vast majority of patients included in our study. Allergy to PEG, polysorbate or their derivatives, the only contraindication to anti-COVID vaccination, according to the recommendations of February 2021, remains rare. Today, several authors propose tolerance inductions allowing the vaccination of patients allergic to PEGs or their derivatives with good tolerance.