MedImmune says it can boost production in 2006 because its newly built plant in England has Food and Drug Administration approval.
The Maryland-based company says the plant can produce up to 15 million doses of FluMist a month.
The product is the only available nasal-spray vaccine for the winter flu. It's also the only vaccine made with live but weakened influenza viruses.
FluMist is suggested for use by healthy people between the ages of 5 and 49.
