The RNA-based Nipah virus, which causes acute respiratory illness and fatal encephalitis, can be transmitted from fruit bats to humans directly or indirectly via pigs or horses. Researchers at Wuhan Institute of Virology, Chinese Academy of Sciences and collaborators wondered whether their oral nucleoside prodrug VV-116, recently licensed against human coronaviruses such as SARS-CoV-2 in China, would be effective against Nipah virus.