Tamiflu Manufacturer Predicted Sales to be Up 531% in 2009

After researching the Annual Report (pdf) of Chugai Pharmaceuticals Co, LTD for the 2008 season, the manufacturers of the drug Tamiflu, it was found that on page 3 there was a prediction by the company that Tamiflu sales would be up 531% to reach ¥53.0 billion. This was all due to government stockpiling.

For the year, we forecast sales of Tamiflu to reach ¥53.0 billion, up 531.0%, due to expected resumption of government stockpiling in FY2009 and the ongoing recovery of the prescription rate for seasonal influenza.

Why would governments be stockpiling Tamiflu? It might be normal to stock up seasonally but to be up 531% from the previous year is rather suspicious… Is it not?