If you check the literature, I think you'll find that the mutagenic effect of ribavirin was seen in vitro studies using much higher doses than those in use in human therapy. The part on ribavirin's MoA from the NEJM paper you cited by Hézode et al is:
Register for free to join our community of investors and share your ideas. You will also get access to streaming quotes, interactive charts, trades, portfolio, live options flow and more tools.