Aug 12, 2005 (CIDRAP News) A week-long meeting of Asian nations just finished in Bangkok resulted in consensus that regional stockpiles of antivirals should be amassed for fast use in the influenza pandemic that is widely expected to emerge from the avian flu strain now circulating. The drug discussed there and focused upon in recent studies touting the usefulness of early treatment and prophylaxis may be joined by another agent in the same class if suggestions in an article released yesterday are taken to heart. Serious question remains, however, over whether pharmaceuticals are really a valid option if a pandemic breaks out in the near future.
The neuraminidase inhibitors oseltamivir (Tamiflu) and zanamivir (Relenza) reduce the severity and duration of symptoms of seasonal flu when given prophylactically or within days after disease onset. Studies are showing some effectiveness against the H5N1 avian flu strain circulating in Asia.
A number of countries, including the United States, have thus begun stockpiling oseltamivir as a weapon against pandemic flu, especially given the fact that a well-matched vaccine would be unavailable early on and production capacity is limited. Other developed countries, too, are buying oseltamivir for their populations.
The World Health Organization (WHO) has a enough of the drug to treat 120,000 people and hopes to build this to 1 million doses shortly, said WHO Director General Lee Jong-wook at the conference in Bangkok. Tamiflu maker Hoffman-LaRoche is considering donating "a substantial amount" of the agent to WHO, according to Reuters. Lee and others have expressed concern that wealthy countries are arming themselves and may not share the drug with the countries where the pandemic is most likely to begin.
Oseltamivir should not be the only agent in the armory, say Kenneth Tsang, from Hong Kong, and his colleagues from Singapore, Malaysia, and Korea in a new Lancet commentary. They suggest that stockpiles of zanamivir be added as well. The agent, which is given as a nasal inhalant, has not surfaced in planning discussions, perhaps because of concern over administration problems in young children and people with intellectual or coordination impairments, they say. "Although both [drugs] have similar efficacy, zanamivir has fewer adverse reactions, and a favorable resistance profile," the authors write, and they claim the concerns could be surmounted.
"This is all well and good," infectious disease expert Michael Osterholm, PhD, MPH, told CIDRAP News, "but people just don't get it. If we were to begin a Manhattan Projecttype response tonight to expand vaccine and drug production, we wouldn't have a measureable impact on the availability of these critical products to sufficiently address a worldwide pandemic for at least several years."
Osterholm, director of CIDRAP, publisher of this Web site, continued, "What we need to do right now is focus on what will get us through a pandemic without counting on drugs. We just don't have a supply chain that can manufacture enough vaccine and antivirals to make a meaningful dent in what we'd need if the pandemic hits in the next 2 or 3 years. We need to think about things like food supplies, healthcare workers and facilities, essential services. We're wasting time."
H5N1 avian flu has killed massive numbers of birds in at least 12 countries in Asia and has spread to other animals and humans there as well. WHO's last official count puts the number of human cases at 112, with 57 deaths. Experts predict that this strain will be the cause of the next pandemic when it achieves the ability to pass efficiently from human to human.
Aug 13 Lancet article by Tsang et al [Full textaccess requires free registration)
CIDRAP's avian flu case count