More than 200 years later influenza is still grabbing headlines. One of the most common and debilitating of global infections, the virus can have a devastating impact on industry, schools and hospitals. Millions of pounds have been invested in trying to beat it, but so far it has defied the best efforts of scientists. So when a new flu cure is mooted, it is guaranteed column inches.
With an eagle eye on its share price, Glaxo Wellcome has seized the opportunity presented by reports of a pre-Christmas epidemic to hype a new potential flu drug, one which is scarcely out of the laboratory.
The company says that a poor flu season last year hampered the development of the compound, known as GG167. There were too few cases to try it on. But this year, the company says confidently, the surge in cases of flu and flu-like illness now being reported has presented the ideal conditions for large-scale clinical trials. It predicts approval from regulatory authorities for a nasal spray or inhalation as early as 1997, with sales in its first year in excess of pounds 200m.
Such confidence in a drug which has been tested in just a handful of human volunteers so far - very few of whom actually had flu - has alarmed drug industry observers and leading scientists. They see a trend developing in which British pharmaceutical companies, once a model of caution, are making claims for compounds still in the preliminary stages of development.
The reasons are clear. The executives of British companies are desperate to retain their dominant position in the global market place, and time is running out. They need new products to replace their top sellers - drugs like Zantac, an anti-ulcer treatment and the best selling drug in the world, but one which loses its patent exclusivity in less than two years' time. Drug companies believe that the "hyping" strategy persuades shareholders to keep the faith. British Biotech, a relatively new company, last week saw its share price shoot up by more than 50 per cent after releasing results of a new anti-cancer drug. The drug, marimastat, had been tested in just 94 patients for one month only.
GG167 is certainly a novel approach to combating the influenza virus. The computer-designed drug does not kill it, but appears to stop the virus in its tracks. It blocks an enzyme, neuraminidase, which is essential for the release of the virus from infected human cells in the nasal passage and the airways of the lungs. The theory is that the immune system will then "mop up" these infected cells and so prevent their spread through the rest of the body.
Peter Collins, a scientist at Monash University in Melbourne, Australia, is credited with discovering GG167 in the mid-Eighties. However, the compound belongs to a much older group of chemicals developed in the Sixties by Peter Palese, a chemist in Vienna. He recognised their potential as anti- viral drugs, but Collins, an X-ray crystallographer, was the one to "fine- tune" the original molecule until it was specific for strains A and B of the flu virus - the most common strains in circulation - sticking to them at a particular point and inhibiting neuraminidase.
Palese's molecule was boat-shaped and fitted a groove in the viral structure neatly enough, according to Professor John Oxford, a leading virologist at the Royal London Hospital in Whitechapel. "What Collins did was add a little oar shape to the molecule so that it fitted even better and had greater efficacy against the virus," he explains.
In the test tube and in laboratory animals, GG167 has proved successful, but in humans there is little in the way of conclusive evidence. Other similar neuraminidase inhibitors are being developed in labs around the world, and there is fierce competition to be first on the market. However, many virologists believe that a simpler back-to-basics approach, now being applied to the Aids virus, is the only way forward against flu: better drugs to treat the symptoms are a more cost-effective option than millions of pounds being invested in potential cures.
But other doctors point to an existing drug as the most exciting prospect for treating influenza A, the most dangerous strain of the virus and the one associated with most fatalities. The drug is amantadine, made by Ciba Geigy and sold as Symmetrel. It is better known as a treatment for Parkinson's disease but its value in flu is widely recognised by those in the know. It is, however, underused because few GPs have heard of it and the Department of Health is not keen to promote it. Flu vaccination for those at particular risk stretches the NHS budget enough as it is. The department has, according to some doctors, overemphasised its side-effects, described as an excess of "jittery" feelings.
A related drug, rimantadine, would reduce these minor side-effects even further, it is claimed. It is rarely used in the West but doctors in the former Soviet Union have regularly prescribed it and have a wide base of patient experience. A few Western drug companies have expressed interest but refuse to comment on its potential as a flu treatment just yet. It is, however, a more realistic option than a hi-tech, state-of-the-art compound which, so far, has proved itself effective at relieving flu symptoms only in laboratory rats and mice.