Every day we inhale thousands of potentially pathogenic fungal spores, but our immune system simply eliminates them. However, in people with compromised immunity, such as transplant and cancer patients, as well as hospitalized patients in intensive care, the interaction between pathogen and host may be quite different.

Fungal infections that emerged during the COVID-19 pandemic, reinforcing the action of SARS-CoV-2 around the world, are a case in point. Mortality reached 80% among severe COVID-19 patients infected with the fungus Aspergillus fumigatus, for example.

A review article by an international group of researchers analyzing SARS-CoV-2/fungus co-infections during the pandemic is published in Nature Microbiology, with warnings relevant to the present and to future pandemics.