The drug Xofluza reportedly can kill the flu virus in 24 hours. It’ll be available in Japan this spring, but it might be next year or even later before it’s in the U.S.

As this winter’s record-breaking flu season finally winds down, a new tool may be available to combat outbreaks in future years.

A Japanese pharmaceutical company recently unveiled a drug that reportedly can kill the flu within 24 hours.

Xofluza, developed by Shionogi, is a single-dose drug that purports to inhibit the virus’ ability to duplicate in the body, although symptoms may still linger for a few days after.

That would set Xofluza apart from Tamiflu, the most similar currently available drug. Tamiflu typically requires five days of twice-daily doses in order to stymie the symptoms of flu, during which time the virus can still be spread to others.

If Xofluza works as quickly and effectively as is claimed, that would be “pretty exciting,” said Dr. William Schaffner, an infectious disease expert at the Vanderbilt University School of Medicine in Tennessee.

“What we have is a very brief report, but if we could take a medicine that only has to be taken once and completely interrupts the virus’ ability to multiply, you’d be able to quickly entail the virus in one patient and make it difficult to give the flu to anyone else,” Schaffner told Healthline. “You wouldn’t give it to family members caring for you, so you’d have two functions and it would be extremely efficient.”

Assuming, he added, it works, is safe, and is reasonably priced.

This winter, 97 children have died from the flu in the United States and the number of hospitalizations reported to the Centers for Disease Control and Prevention (CDC) has surpassed its previous high.

Out of every 10,000 Americans, 7.5 of them have suffered flu symptoms bad enough to be hospitalized, the agency estimates.

A drug that could fight the flu within hours could go a long way toward preventing such outbreaks in future years.

The flu vaccine is the main defense, but this year’s vaccine only reduced Americans’ risk of having to visit a doctor regarding flu symptoms by 36 percent, according to the CDC.

And given that a new cocktail has to be crafted each year, having a faster second line of defense that could work year after year no matter how the flu virus changes, could reduce both the spread and costs of the virus.

“If it’s even half as good as it’s touted to be, it could have a substantial impact,” Schaffner said. “If it works, it would shift the cost-benefit equation to the benefit side.”

Schaffner said that’s because it could eliminate the costs of going to the doctor or emergency room or long hospital stays.

The new drug has already been approved by Japan’s Ministry of Health through a fast-track approval process.

It’s expected to be available in Japan in May.

Shionogi reportedly plans to submit their drug for approval in the United States this year, but that approval is unlikely to come until 2019 or later.

A Food and Drug Administration (FDA) spokesperson said the agency is only able to provide information about approved drugs, not potential applicants for approval.

The agency plans to complete reviews within 10 months for most drugs, and six months for drugs given the designation “priority review.”

But it has also been trying to speed up reviews, particularly for generics, in recent years.

As far as safety goes, “there’s no such thing as a completely safe medicine or vaccine,” Schaffner said. “Once it starts to be used by thousands of people, you have to keep monitoring it because sometimes there are only effects that appear in, say, one of hundreds of thousands of people.”

But Schaffner sees this as a dramatic breakthrough. Tamiflu and two similar drugs were the last innovations in flu therapies, he noted.