A Japanese pharmaceutical company claims a pill it has developed can kill the flu virus in a single day, 9 News reports.

The news comes amid what many health experts are referring to as one of the worst flu seasons in years for Americans.

Baloxavir is a flu drug co-developed by Shionogi & Co. and Roche Holding AG. It won’t be available in the U.S. until next winter.

Japan has granted the drug preliminary approval and developers plan to file for regulatory review in Europe and the U.S. later this year, according to reports.

During trials, a single does of Baloxavir destroyed the flu virus within 24 hours. That’s three times as fast as Roche’s Tamiflu which is currently available.

The current treatment for the flu via Tamiflu requires taking 10 doses over the course of five days.