Drugs No Answer to Bird Flu: Experts

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http://www.commondreams.org/headlines05/1010-08.htm

 

Published on Monday, October 10, 2005 by Reuters

Drugs No Answer to Bird Flu: Experts

by Maggie Fox

 

 

Many governments around the world are stockpiling antiviral drugs and

some companies are trying to speed up vaccine production but these

measure give a false sense of security and will do little to counter a

flu pandemic, an expert cautioned on Monday.

 

 

French doctor Alix Greder-Belan demonstrates the use of a protective

face mask to be used by hospital staff in case of a bird flu pandemic

at the Mignot Hospital in Versailles October 10, 2005. The Mignot

Hospital in Versailles, west of Paris, received a shipment on October

10, 2005 of some 130,000 of the face masks for use by hospital

employees for protection against contagious avian influenza. The

European Commission announced a ban on Monday of all imports of live

birds and feathers from Turkey into the 25-nation EU on Monday after

Ankara confirmed an outbreak of a highly contagious avian influenza.

 

Michael Osterholm, an infectious disease expert who has been studying

the risk of pandemic flu for decades and is a U.S. government adviser,

said governments should be preparing to cope with the pandemic instead

of relying entirely on the hope of using vaccines and drugs to control it.

 

If the H5N1 avian flu begins to easily infect humans, it will move too

quickly for drugs and vaccines to be of much use, Osterholm said.

 

" It doesn't matter if we have a vaccine now or not. We can't make it, "

Osterholm said in a telephone interview.

 

The H5N1 bird flu virus has killed at least 65 people in four Asian

nations since late 2003, and has killed or forced the destruction of

tens of millions of poultry.

 

Experts say it is mutating steadily and fear it will eventually

acquire the changes it needs to spread easily from person to person.

 

If it does, it will sweep around the world in months or even weeks and

could kill millions of people -- as many as 150 million, according to

the most dire forecast by the World Health Organization.

 

When avian flu infects people it looks like any other flu with

respiratory symptoms, fever and other common effects but it will kill

many more than the 500,000 people who die of ordinary flu each year

around the world.

 

People have known about the risk of an influenza pandemic for a very

long time, said Osterholm, an infectious disease specialist at the

University of Minnesota who advises the federal government on such issues.

 

" We have had a pandemic flu plan as a planning process since 1976, "

said Osterholm. " Nobody has completed it. It been one of the most

long-standing incompleted processes in Washington. Nobody wants to

believe that modern medical science can't handle something. "

 

But it cannot, said Osterholm, who has seen the current U.S. flu plan.

The plan has not been published yet but leaked versions suggest the

country has done little to prepare for an H5N1 pandemic.

 

Osterholm and other experts have long been complaining that there are

not sufficient hospital beds, equipment or trained workers to cope

with a major epidemic.

 

" The one thing I worry desperately about it is the impact of

overreliance on neuraminidase inhibitors, " he said.

 

There are two drugs in the class -- Roche and Gilead's Tamiflu, known

generically as oseltamivir, and GlaxoSmithKline's Relenza.

 

They work to reduce the severity of annual influenza and may prevent

infection if used at the right time. Tests suggest they also work

against H5N1, but no one knows how well.

 

" I think that potentially neuraminidase inhibitors may work if you are

already on them as prophylaxis (prevention), " Osterholm said. That

would mean taking them daily for days or weeks.

 

" That means that very, very limited supply is going to become a lot

more limited. "

 

FIGHTING OVER SCARCE SUPPLIES

 

The United States has enough courses of Tamiflu to treat about 2.3

million people. The Health and Human Services Department says another

2 million treatment courses are on order and will arrive by the end of

the year.

 

But some 90 million people would need the drug in the event of a flu

pandemic, University of Virginia flu expert Dr. Frederick Hayden told

a meeting on Saturday.

 

At current capacity, it would take about 10 years to produce enough

oseltamivir to treat 20 percent of the world's population, Hayden said.

 

" Now people are saying whoever has the most Tamiflu wins, " Osterholm

said. " I worry so much that Tamiflu is a surrogate for protection. "

 

And vaccines are not an answer yet and will not be for years. There is

an experimental vaccine against H5N1 but there are only a few thousand

doses of it.

 

It takes months to make influenza vaccine and H5N1 kills chickens --

the source of the eggs that are needed under current old-fashioned

production methods to make flu vaccines.

 

Companies are trying to develop more modern methods but are years away

from doing so. And work cannot begin on a true vaccine against H5N1

until it actually starts infecting many people, because the vaccine

must match the virus precisely and no one can predict just how H5N1

will mutate.

 

And it is mutating.

 

A study published last week showed that the H1N1 virus that caused the

1918 flu pandemic, which killed at least 40 million people globally

and may have killed more, depending on estimates, was a purely avian

virus that acquired a few mutations that gave it the ability to infect

people easily, spread among them and cause highly fatal disease.

 

H5N1 is mutating in a similar way and experts believe it is only a

matter of time before it, too, infects people easily.

 

© Copyright 2005 Reuters Ltd

 

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