By LEE BOWMAN
Scripps Howard News Service
November 02, 2005
While acknowledging during at speech Tuesday at the National Institutes of Health in Bethesda, Md., that there's currently no influenza pandemic in the United States or the world, Bush echoed concerns raised by public health officials around the globe that "at some point we are likely to face another pandemic" arising from bird flu.
Most of the money he proposes to spend would be devoted to stockpiling anti-viral medications and 20 million doses of an experimental vaccine against the bird-flu strain circulating in fowl from Asia to Europe this fall, H5N1. He also wants to invest more federal dollars in an international flu-surveillance network and boost, by $100 million, federal funding to state and local public health agencies.
Federal plans would also lay the groundwork for infection-control measures such as mass quarantine and travel restrictions to be used in this country on a scale not seen in at least 50 years.
"In a pandemic, an infection carried by one person can be transmitted to many other people, and so every American must take personal responsibility for stopping the spread of the virus," Bush said.
While public health officials are generally supportive of the president's initiative, some experts question whether the talk of preparedness fuels needless worry about an epidemic that may never come.
"We need to remember that this is currently a bird disease and may remain so," said Dr. Marc Siegel, an associate professor of internal medicine at New York University. "The potential widespread effects of an eventual pandemic are worthy of preparation by our government, but not panic in the general public."
Here, in a Q&A format, is a look at some of the concerns involved:
Q: Just what is bird flu and how can it affect people?
A: There are a number of influenza viruses that birds can carry, and outbreaks crop up among birds often. The H5N1 strain causing concern now first surfaced in Hong Kong eight years ago, and has been circulating through several countries in Asia for the past two years. Although domestic poultry has been the focus of bird-flu worries, wild birds can also carry the disease.
At least 120 people in several Asian countries have contracted bird flu, mostly from contact with poultry on farms and in markets where live birds are sold. More than 60 people have died from the virus. But with one possible exception, no one has caught the illness from another infected human.
Q: Why is the virus so deadly?
A: It has a new type of protein on its surface that humans have not developed any immunity against. That means it can spread rapidly through cells and cause organ failure.
Q: What has to happen to trigger a pandemic?
A: The big fear among virologists is that bird flu and an ordinary seasonal flu will infect a person or persons at the same time and swap genes to create a hybrid virus that people could easily pass to one another by sneezing and coughing. Scientists know that this kind of mixing happened three times in the last century to produce pandemics. It's also possible, though less likely, that the virus might evolve on its own to become more transmissible. But it's also possible that a mutated virus might spread more easily but result in a less severe illness in humans.
Q: If a new human-to-human strain did arise, how fast would it spread?
A: The experience with Severe Acute Respiratory Syndrome (SARS) three years ago demonstrated that in the jet age, disease could travel around the world in a day. Most experts think a flu pandemic could take hold in a few weeks or months, and could linger for a year or two. The World Health Organization projects that between 2 million and 7.4 million people could die.
On the other hand, some experts note that the very mobility of disease may offer some edge against a hybrid flu, because most people around the globe are exposed to new flu strains every winter and build some immunity in the process.
Q: What about the vaccine the government's stockpiling?
A: There are several prototype vaccines being tested and produced. The concern is that any vaccine that works against today's H5N1 strain might not be effective against a mutant form that sparks a global outbreak. Even if the vaccine was a good match, the shots the government wants to stockpile are being made using egg cultures that take months to grow.
The upshot is that unless new cell culturing or DNA-based vaccine-technology gets rolling - which Bush's plan encourages - there's only going to be enough vaccine for maybe one in three people in this country within the first year of an outbreak.
Q: What about Tamiflu and Relenza?
A: Those two anti-viral drugs that fight regular flu are thought to be effective against H5N1 if they are given within the first 24-48 hours of infection. The government wants to stockpile tens of millions of doses of these drugs, but supply is also limited. Roche Pharmaceuticals, the maker of Tamiflu, suspended most shipments last week to discourage private hording and to ensure that there's enough of the drug around this winter to treat high-risk patients for ordinary flu.
There's also considerable concern that if people start taking the drugs to ward off infection, flu viruses may become even more resistant to drugs and worsen. There have been reports that at least one sample of H5N1 virus has proven to be resistant to Tamiflu.
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