Tamiflu, the brand name for the drug oseltamivir, has been found to curb the worst effects of one common flu virus in carefully-controlled tests.

But whereas Relenza is available in the form of an inhaled powder, Tamiflu comes in tablet form, making it even more convenient for sufferers.

The research, published in the Journal of the American Medical Association, and carried out by the University of Virginia, tested the drug on people artificially infected with the influenza 'A' virus.

They found that on average, those taking the tablets suffered flu for only 53 hours as opposed to 95 hours for those given no treatment - a reduction of 45%.

Headed off complications

This helped stop some flu sufferers from developing complications such as further respiratory tract infections.

This roughly compares with the efficacy of Relenza, which has roughla 40% reduction in duration of illness, although studies have shown benefits against another form of flu - the influenza 'B' virus.

Both drugs work in the same way, inhibiting the virus' ability to reproduce and spread throughout the body.

Court action

Drug firm GlaxoWellcome, which makes Relenza, may embark on a court battle to force the government to make the drug available on the NHS, after a key advisory body decided there was not sufficient evidence that it worked on those at highest risk of flu, such as the elderly.

Their five-day treatment costs £24, and there were some fears that it could cost the NHS more than £100m in the event of a flu epidemic year, also Glaxo dispute this.

The National Institute of Clinical Excellence (NICE) was set up by the government to examine new treatments and decide whether they arcost-effective.

If Tamiflu, made by Hoffman-LaRoche, is to be launched in the UK, it is likely that NICE will also be asked to look at the evidence that it works.

A team of Belgian researchers claims to have found a breakthrough which could allow people to have just one vaccination to prevent flu for a lifetime.

At the moment patients have to be inoculated regularly as fresh strains of flu emerge each year.

The government is preparing to launch its campaign encouraging high risk groups such as asthma sufferers or the elderly to get vaccinated.

Last year approximately 40% of people in these groups came forward to have the inoculations.