Ensitrelvir fumarate is primarily used in the development of antiviral medications, particularly targeting RNA viruses. Its application is significant in the treatment of viral infections, where it inhibits viral replication by targeting specific viral enzymes. This makes it a potential candidate for therapies against emerging viral diseases. Research is ongoing to explore its efficacy in clinical settings, especially in combating infections that lack effective treatments. Its role in antiviral drug development highlights its importance in public health, particularly in managing outbreaks and pandemics.