The drugs giant, Roche, said on Monday that it had received approval from the United States Food and Drug Administration to market Tamiflu as a preventative medicine against influenza.
The decision means that Tamiflu will be available this winter as a preventative drug.
It was approved by the FDA in October 1999 as a treatment for those already showing symptoms.
Around 40 million Americans develop the flu every year.
Roche developed Tamiflu in collaboration with Gilead Sciences. It helps prevent all common strains of the flu virus.
The use of the drug in preventative treatment is still awaiting approval in a number of markets including Canada.
swissinfo with agencies