Dexamethasone treatment does not alter mortality but reduces pulmonary pathology in Nipah virus-infected Syrian hamsters

Nipah virus (NiV) is an emerging zoonotic pathogen that causes severe respiratory and neurologic disease, and there are currently no licensed vaccines or approved treatments. The acute respiratory disease caused by NiV is associated with severe inflammatory disease, similar to severe COVID-19. Dexamethasone is an affordable and widely available synthetic glucocorticoid, and when administered to patients with severe COVID-19 improved outcomes. Here we tested the effect of dexamethasone on NiV in the Syrian hamster model, both on its own and combined with the antiviral drug, remdesivir. We found that dexamethasone treatment produced the expected hematologic changes in uninfected animals when administered at anti-inflammatory or immunosuppressive doses in a dose-dependent manner. In NiV-infected animals, dexamethasone reduced pulmonary pathology but did not alter mortality, even when combined with remdesivir, which would improve survival when administered alone. Our study provides critical information on the effect of dexamethasone on NiV infection.