Do eosinophils exert antiviral activity in COVID-19
patients?
Anti-IL-5 treatment, which induces eosinophil deficiency, results in a
higher viral load in influenza and rhinovirus infection. This might be
due to the ability of eosinophils to bind and inactivate the influenza A
virus and respiratory syncytial virus (RSV).53 A
similar role seems possible in SARS-CoV-2 infection, where type-2 asthma
patients potentially benefit from antiviral eosinophil responses. On the
other hand, COVID-19 post-mortems did not show lung
eosinophilia51, which argues against its local
protective role in SARS-CoV-2 infection, although it is important to
control for glucocorticoid-driven eosinophil reduction in these
studies.50