Eosinophil Response During COVID-19 Infection and Vaccination

Eosinophil cells
Eosinophil cells
Considerable concern exists over whether SARS-CoV-2 exposure postvaccination will cause eosinophil-associated lung pathology through immunopotentiation.

Considerable concern exists over whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure postvaccination will cause eosinophil-associated lung pathology through immunopotentiation, according to a review article published in the Journal of Allergy and Clinical Immunology.

Eosinopenia has been reported in patients with acute respiratory deterioration during infection with SARS-CoV-2, the causative agents of COVID-19. There are several key COVID-19 eosinophil-related questions; the answers of which will affect recommended prevention and care.

Therefore, the review authors sought to address these questions in patients with eosinophil-associated diseases. They found that there is no evidence that patients with eosinopenia induced by recently approved anti-eosinophil therapeutics have increased susceptibility to viruses. In addition, whether the acquired eosinopenia associated with COVID-19 is directly contributing to the disease course has not yet been determined, but pulmonary eosinophilia is not part of the lung pathology attributed to SARS-CoV-2 so far. However, to determine the role of eosinophils in COVID-19 lung pathology, it will be important to assess the presence of eosinophils and the deposition of their granule products in large cohort of patients with COVID-19.

The ongoing COVID-19 pandemic places a significant emphasis on the critical need for an effective SARS-CoV-2 vaccine, but safety must be a central focus for any vaccine designed for general use.

“Although current data are limited, there is little supportive evidence that patients with eosinophil-associated diseases will have an altered course of COVID-19, provided that they are not immunosuppressed from concurrent medications or by their primary disease process,” the review authors concluded. “Current clinical reports show that the majority (up to 81%) of patients with COVID-19 have mild disease, and therefore, trials of vaccine candidates must rigorously demonstrate the absence of eosinophil-associated disease enhancement prior to widespread deployment.”

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Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Lindsley AW, Schwartz JT, Rothenberg ME. Eosinophil responses during COVID-19 infections and coronavirus vaccination [published online April 25, 2020]. J Allergy Clin Immunol. doi:10.1016/j.jaci.2020.04.021