Tamiflu has been recognised by the World Health Organisation as the first-line treatment of choice for bird flu or A/H5N1, tipped to be the most likely strain of the virus to cause a human pandemic. The WHO recommends that all centres that deal with flu outbreaks have sufficient supplies of the drug on hand.
But Roche is struggling to keep up with burgeoning demand for Tamiflu, with new customers facing a waiting time of up to two years.
The Swiss firm has already donated 120,000 courses of the drug to the WHO, but this is likely to be only a fraction of the number needed in the event of an outbreak. Moreover, developed countries are now inundating Roche with orders for the drug, spurred by WHO warnings that a bird flu epidemic could lead to 28 million infections and cause 7 million deaths.
WHO has urged all its member states to develop or update their influenza pandemic preparedness plans 'as a matter of urgency'. And several countries, mostly developed ones, have already published updated preparedness plans.
The UK has announced plans to procure 14.6 million courses of Tamiflu, while France, Switzerland, Finland and Germany have also placed big orders. This could exacerbate shortages even though any pandemic is likely to originate in developing regions, particularly in Asia, according to the WHO.
Roche said it would strive to meet future demand by opening a new plant in North America in the second half of this year.
The WHO is recommending that more affluent countries look to vaccination strategies. Although current flu vaccines would not offer protection against a future pandemic strain, the increasing likelihood that the next pandemic strain will originate from H5N1 - and may not differ from it significantly - means that stockpiling vaccines against this strain may be a viable option.
Since January 2004, when human cases of H5N1 avian influenza were first reported in the current outbreak, 97 cases and 53 deaths have been reported in Vietnam, Thailand and Cambodia. Vietnam, with 76 cases and 37 deaths, has been the most severely affected country, followed by Thailand, with 17 cases and 12 deaths, and Cambodia, with 4 cases and 4 deaths.