Drug Effective Against Avian Flu

Relenza is very effective against human strains

Feb. 20, 2004

A drug used to treat flu has been shown to be effective against the avian strain of the disease sweeping Asia.

The Commonwealth Scientific and Industrial Research Organisation in Australia tested the drug, Relenza, on a sample of the H5N1 virus.

The virus has killed 22 people in Asia, and infected millions of chickens.

The tests showed the drug was as effective at stopping H5N1 from multiplying as it was against other strains of flu that affect humans.

If the virus begins to spread from human to human we could be totally dependent on these drugs. — 
Professor John Oxford

Relenza was launched on the world market in 1999. It is based on a CSIRO discovery that there is a small section on the surface of the flu virus that does not change between different strains.

Relenza works by inhibiting proteins on the surface of this section of the virus so it cannot replicate.

It has proved to prevent transmission of flu in about 80% of cases, and has also been effective in reducing symptoms in people who have been infected.

A second drug, Tamiflu, was subsequently developed based on the same research.

Its manufacturers claim that pre-clinical trials show it may also be effective against avian flu.


Major threat

The current strain of avian flu has not been shown to pass from human to human, although there is concern that the virus will combine with a human form, and then pose a major threat.

At present, all those who have died from this disease have caught it directly from infected birds.

The current strategy for preventing this virus from spreading further and endangering more humans has been to cull millions of chickens in Asian farms and markets.

Lead researcher Dr Jenny McKimm-Breschkin said: "In the event that the disease does mutate into a form which can be passed from human to human it is important to know that we already have a treatment available.

"The fact that our experiments show that in the laboratory this drug is effective against bird flu again shows just how important a discovery this was."

Further research will be needed to establish that Relenza is effective in humans infected with avian flu.

Professor John Oxford, an expert in virology at St Bart's Hospital, London, urged the international community to stock up on supplies of Relenza and Tamiflu.

He told BBC News Online: "If the virus begins to spread from human to human we could be totally dependent on these drugs.

"It is nice to know that there is something in the medicine cupboard that can block this virus, but if the virus was to strike now we would still be in a dire situation, as it would take up to a year to build up sufficient supplies.

"That is a poor indication of the way we have all been too complacent about the threat that viruses like this pose."

http://news.bbc.co.uk/1/hi/health/3505739.stm