A small study of children with influenza in Japan estimated that the influenza virus can thwart a drug that was thought to be relatively foolproof. The paper, published in the August 28 issue of The Lancet , just as some countries stockpiled the same antiviral drug against pandemic influenza. researchers flu say there is no need to stop storage, though - the drugs must always be useful
The last major global flu pandemic, the Spanish flu of 1918, killed 50 million people .. another great pandemic could be in the works if the avian flu H5N1 highly virulent, which killed at least 24 people in Asia last winter takes a form that can be transmitted from person to person. Because the preparation of a vaccine against such a virus might take six months, antiviral drugs are the first line of defense against pandemic flu. Although the flu virus may develop resistance to some older drugs, new drugs called neuraminidase inhibitors that target an enzyme that makes an envelope of the influenza virus protein, appeared more waterproof. Thus, some countries have started to store any of these drugs, oseltamivir (sold as Tamiflu).
The United States is among them, according to a federal pandemic flu plan released today. The United States has stockpiled enough oseltamivir to treat 1 million people, officials said. The plan also describes measures to increase vaccine manufacturing capacity and how national and local health care providers should respond.
The Lancet report, however, suggests that the influenza virus develops resistance to oseltamivir easier than was thought. Virologist Yoshihiro Kawaoka of the University of Tokyo and his colleagues in Japan and the United States has collected virus samples from 50 children after a 5-day course of oseltamivir for an episode of the flu. In nine samples, 18% of children, the virus had developed mutations that made it resistant to the drug.
But this does not mean antivirals will not work against a pandemic, says Kawaoka, who is also at the University of Wisconsin, Madison. On the one hand, the changes that make an oseltamivir-resistant virus may make it less pathogenic, he said. In an accompanying editorial, Anne Moscona of Mount Sinai School of Medicine in New York noted that another drug in this class, zanamivir, may be less likely to become resistant.
Moreover, adds expert Arnold Monto flu the University of Michigan, Ann Arbor, strains of avian influenza will not necessarily become resistant to oseltamivir as easily. Monto, who sits on an international committee that recently recommended the storage of neuraminidase inhibitors in August 13 Weekly Epidemiological Record , concludes: "The message for most of us, governments. should stockpile "
Related Sites
neuraminidase Inhibitor susceptibility Network statement supporting the antiviral storage
US response Ministry pandemic Health and Human Services and preparedness Plan
0 Komentar