The data: While favipiravir, an antiviral made by Toyama Chemical (part of Fuji Film), generated hopeful headlines, the report from doctors at China’s Wuhan University makes more modest claims. They organized a study of 240 “ordinary” patients (meaning they had pneumonia but were not the worst cases) around Hubei province. Half got favipiravir and half got umifenovir (or Arbidol), an antiviral used in Russia, and they were watched to see which group recovered faster. The doctors found that patients’ fevers and coughs went away faster on favipiravir, but similar numbers in each group ended up needing oxygen or a ventilator. On the basis of these findings, they concluded that favipiravir is the “preferred” of the two drugs.

Favipiravir, which is known by the trade name Avigan in Japan, inhibits viruses from copying their genetic material. It was originally discovered while searching for drugs to treat influenza.