Two days after infecting groups of guinea pigs with a lethal dose of Lassa virus, the scientists treated the rodents daily for two weeks with either ribavirin, low doses of favipiravir, or high doses of favipiravir. They also evaluated the effect of high-dose favipiravir in the rodents that began treatment five, seven or nine days after infection. All of the animals that received high-dose favipiravir were completely protected from lethal infection; animals treated seven or nine days after infection had begun showing signs of disease, but their conditions quickly improved when treatment began. Those animals in the low-dose favipiravir group showed mild to moderate signs of disease, but those symptoms resolved after about one week of treatment. The animals treated with ribavirin appeared normal during the treatment phase but developed severe disease shortly after treatment ended.

Further testing and human clinical trials are needed to determine if favipiravir, also known as T-705 and Avigan, could effectively treat Lassa virus infection in people.

Story Source:

The above post is reprinted from materials provided by NIH/National Institute of Allergy and Infectious Diseases. Note: Materials may be edited for content and length.

Journal Reference:

1. David Safronetz, Kyle Rosenke, Jonna B. Westover, Cynthia Martellaro, Atsushi Okumura, Yousuke Furuta, Joan Geisbert, Greg Saturday, Takashi Komeno, Thomas W. Geisbert, Heinz Feldmann, Brian B. Gowen. The broad-spectrum antiviral favipiravir protects guinea pigs from lethal Lassa virus infection post-disease onset. Scientific Reports, 2015; 5: 14775 DOI: 10.1038/srep14775