After the worst flu season in nearly a decade, a new drug could revolutionize how we treat the seasonal virus. The FDA agreed to fast-track a review of a one-time dose, baloxavir marboxil, that’s shown impressive results in Japan. It shortens flu symptoms by more than a day and also cuts the risk of spreading the virus to other people.

“This is the first drug that actually blocks production of new virus. So you take it in one pill and it blocks the production of the virus and shortens the duration of the flu. It makes you feel better,” Dr. David Agus told “CBS This Morning” on Thursday.

Agus explained that it differs from Tamiflu, the antiviral drug most commonly used to treat the flu, because it stops the virus from being spread in one day instead of three days. Tamiflu also requires more doses, two per day for five days.

“When you look at public health, that’s exactly how you want it,” Agus said. “This is a way of really, hopefully stopping the virus in its tracks. You saw entire schools closed for days this year.”

It’s unclear how much it will cost in the U.S. but in Japan it’s priced at $43 for one pill. The FDA has agreed to give its answer by the end of the year.

“Certainly we hope to have an answer from the FDA by the end of the year and have this on the market. It’d be a hell of a Christmas present for all of us,” Agus said.

Even if it is approved, though, everyone should get the flu shot.

“It’s still a lot better to prevent the flu than to treat the flu.”