Ebola virus dynamics in mice treated with favipiravir

• Favipiravir is a nucleotide analogue with potent antiviral activity against Ebola virus.
• We analyzed the Ebola viral kinetics in mice untreated or treated with favipiravir using a mathematical model.
• The productively infected cell half-life was ∼6 h and the number of infections induced by one infected cell was ∼9.
• Favipiravir antiviral effectiveness in blocking viral production was >99% after two days of treatment.

The polymerase inhibitor favipiravir is a candidate for the treatment of Ebola virus disease. Here, we designed a mathematical model to characterize the viral dynamics in 20 mice experimentally infected with Ebola virus, which were either left untreated or treated with favipiravir at 6 or 8 days post infection. This approach provided estimates of kinetic parameters of Ebola virus reproduction, such as the half-life of productively infected cells, of about 6 h, and the basic reproductive number which indicates that virus produced by a single infected cell productively infects about 9 new cells. Furthermore, the model predicted that favipiravir efficiently blocks viral production, reaching an antiviral effectiveness of 95% and 99.6% at 2 and 6 days after initiation of treatment, respectively. The model could be particularly helpful to guide future studies evaluating favipiravir in larger animals.