The new pill that could signal the death of the common cold

The 'holy grail of cold research', it could be used to clear up sniffles in healthy people and prevent life-threatening infections in asthma and cystic fibrosis sufferers.

Trials on hundreds of British volunteers started yesterday.

If successful, the cold-busting pill could be on the market in five years.

The common cold: Have scientists discovered the 'Holy Grail of cold research'?

Effective against the bugs that cause half of colds in adults and almost all colds in children, it could net its Australian creators billions of pounds a year.

The drug, which is known as BTA798, latches on to cold-causing human rhinoviruses (HRV), preventing them breaking into the body's cells and causing infection.

In a double-pronged attack, it also stops any infection that has taken hold from spreading.

In lab tests, the drug killed large quantities of cold virus within a couple of hours.

The first limited human trials finished last year and showed BTA798, which is being developed by Victoria-based Biota Holdings, to be safe.

Peter Cook, the company's chief executive officer, hailed the results as 'a significant milestone in the development of what could be a world-first antiviral treatment for HRV in high-risk patients'.

Larger-scale trials are now under way to determine whether it can actually prevent people from catching a cold.

Two hundred healthy people will be given the drug or a dummy pill before being exposed to human rhinovirus.

Three different doses of the drug will be used, in order to determine which, if any, can keep the infection at bay.

If it proves successful, several more years of tests involving thousands of volunteers will be needed before the drug hits the market.

By the time we are 70, we will have spent three years of our lives coughing and sneezing

Biota Holdings, the developers of the flu treatment Relenza, are likely to first market it for chronically ill patients whose conditions are made worse by colds.

HRV frequently exacerbates asthma, which is one of the main reasons why asthmatics end up in hospital after catching a cold.

Other high-risk groups include sufferers of cystic fibrosis, bronchitis and emphysema and those with weakened immune systems.

However, British experts say the drug is also likely to hit the mass market.

Professor John Oxford, a leading virologist, said: 'I think their intention is to move into common or garden colds, which are not the sort of thing you want to have in the middle of August or any time.

'You just don't want it to interfere with your life. But the common cold also has a serious side.

'If you are a five-year-old and you have got some other kind of medical problem like asthma, a cold can make you into a little medical crisis.'

He added: 'If the promise is fulfilled, they will have a bonanza area.'

It is unclear how the drug would be taken but Professor Oxford, of Queen Mary's School of Medicine in London, said it was likely it could be used to both treat colds and ward them off.

For instance, taking the drug at the first sign of the sniffles could prevent the cold from progressing further.

Those afraid of catching a cold from a relative or colleague could also reach for the pills.

'I would take it if my wife or someone close to me had a common cold but you wouldn't want to take it all the time,' said the professor.

He added that the drug would need to have few, if any, side-effects if it were to be embraced by the public as a treatment for a condition that rarely causes serious harm.

The search for a cure for the common cold has until now been stymied by the vast array of viruses that can cause the condition.

But BTA798 has been custom-built to defeat numerous strains of HRV.

By the age of 70, most people will have clocked up around 200 colds and spent three years coughing and sneezing.