Molnupiravir(MK-4482);EIDD-2801 is an orally bioavailable form of a highly potent ribonucleoside analog that inhibits the replication of multiple RNA viruses including SARS-CoV-2, the causative agent of COVID-19. EIDD-2801 has been shown to improve pulmonary function, decrease body weight loss and reduce the amount of virus in the lung. In addition to activity against coronaviruses, EIDD-2801, in laboratory studies, has demonstrated activity against seasonal and bird influenza, respiratory syncytial virus, chikungunya virus, Ebola virus, Venezuelan equine encephalitis virus, and Eastern equine encephalitis virus. EIDD-2801 is a prodrug of EIDD-1931.