Scientists from the University of Wisconsin-Madison, working with colleagues in Vietnam and Japan, report in a brief communication in next week's edition (Oct. 20, 2005) of the journal Nature that a young girl, provided with a prophylactic dose of the drug after experiencing mild influenza symptoms, developed a strain of the virus that was highly resistant to the drug.
The finding suggests that health officials - now stockpiling millions of doses of the drug to forestall a global outbreak of influenza and buy time to develop and mass produce a vaccine - should also consider other options, according to Yoshihiro Kawaoka, an international authority on influenza and the senior author of the Nature paper.
Recent reports indicate the federal government may spend billions of dollars to stockpile as much as 81 million courses of Tamiflu to forestall a possible influenza pandemic. The government has already stockpiled an estimated 12 to 13 million courses.
"This is the first line of defense," says Kawaoka, a professor in the UW-Madison School of Veterinary Medicine who holds a joint appointment at the University of Tokyo. "It is the drug many countries are stockpiling, and the plan is to rely heavily on it."
The drug would be used to slow the spread of influenza until a vaccine is developed, which may take up to six months.
Tamiflu is delivered orally and works to impede the spread of the virus by binding to and inhibiting one of the surface enzymes the virus uses to exit infected cells of a host. Once inside a host cell, the virus commandeers the cell's reproductive machinery to make new infectious particles that go on to take over other c
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Contact: Yoshihiro Kawaoka
kawaokay@svm.vetmed.wisc.edu
608-265-4925
University of Wisconsin-Madison
14-Oct-2005