BIG BUSINESS: Pharmaceutical companies have started recognising anti-viral drugs as lucrative

Top US scientists at federal health institutes, universities, and drug companies report that they are witnessing a surge of interest in finding treatments for viral infections ? fuelled in part by fears of a global flu epidemic.

Once, viral disease researchers rarely heard from drug development companies. Now, scientists say, they regularly get calls from companies hoping to forge partnerships in the quest to discover anti-viral medicines.

Scientists say they could be at the dawn of an unprecedented period of discovery in the hunt for drugs against viruses that cause hepatitis, respiratory ailments, and more exotic diseases.

The US government’s top disease specialist, Dr Anthony S. Fauci, said the threat of a bird flu virus that could kill millions of people has compelled scientists to reconsider their research priorities. “This kind of attention is causing us to shake the cages,” Fauci, director of the National Institute of Allergy and Infectious Diseases, said at a flu preparedness summit in Boston last month. “We’ve accepted less-than-optimal viral treatments. We’ve got to do better than that.”

The campaign against bio-terrorism also has boosted research on viruses, leading the government to more than double spending on the war against deadly germs in the past five years.

For decades, medicines to fight viral infections have been a neglected aspect of drug research.

While viruses and bacteria both cause enormous human suffering, it’s always been a lot easier to find bacteria-slaying antibiotics like penicillin, because they occur naturally wherever bacteria live, such as in the soil.

There’s no such luck when it comes to anti-virals. They have to be made in the lab, and scientists have to be careful not to cause collateral damage: Viruses invade human cells, so drugs to combat those germs must work like smart bombs to avoid damaging cells.

But the fears that bird flu could develop the ability to spread rapidly among humans, advances in research technology, and the growing realisation that there’s money to be made in anti-virals is starting to change the landscape.

“There’s been momentum building for anti-virals, perhaps picking up more recently with more intensity,” said Dr Raphael Dolin, dean for Academic and Clinical Programs at Harvard Medical School. “The paradox has been that viral infections are so prevalent and so important, and yet the number of anti-viral drugs that have been developed are relatively few compared to antibiotics.”

There’s no disputing the need: There are more drugs aimed at HIV ? about two dozen ? than there are for all other viral ailments combined.

There are the viral bugs that cause millions of colds and those responsible for the flu. And there are viruses that while far less common are much more lethal: In every African outbreak of Ebola during the past three decades, more than half of those infected have died.

Companies increasingly appear to recognise that what makes good medical sense can also make good business sense. The Swiss drug giant Roche Pharmaceuticals saw revenue from its flu-pill Tamiflu soar more than fivefold in a single year, rocketing from $229 million in global sales in 2004 to $1.2 billion a year later. And a report from the global consulting company Frost & Sullivan forecasts that the US market for drugs against hepatitis B and C will increase from about $2.2 billion last year to nearly $4.8 billion in 2012.

At least once a week, drug companies with a new virus-fighting strategy approach scientists at the US Centers for Disease Control and Prevention and ask for help ? a level of interest not evident until the past year, said Rick A. Bright, who until last month directed the anti-viral drug program in the CDC’s Influenza Branch.

Bright said he believes that lessons gleaned by drug researchers in the pursuit of new influenza medications can be translated to other viral conditions. “Once they start learning the basics of anti-viral drug development, they gain that experience, and they become much more interested in developing other anti-virals,” said Bright.

Still, finding new drugs to treat viruses will never be as simple as scooping up a cup of dirt.

The British researcher Alexander Fleming stumbled upon the world’s first antibiotic, penicillin, when he noticed that mold sprouting in a laboratory experiment had strangled the advance of bacteria. That was in 1928.

It would take another three decades before scientists introduced the first anti-viral, a drug used to treat herpes infections in the eye. The anti-virals that followed were the product of painstaking laboratory discoveries.

“I can't think of any anti-virals that are licensed for use that were originally developed from natural products,” said John Coffin, who specialises in studying the AIDS virus at Tufts University. “But with anti-bacterials, it was a fairly simple matter to go into the soil or the sewer and start pulling out things and testing them in a very simple way to determine if they inhibited bacteria.”

Bacteria possess an array of mechanisms that can be targeted by drugs. And because bacteria aren’t dependent on humans for survival and replication, drugs can kill bacteria without killing human cells. Studying bacteria in the laboratory is also a straightforward process, with scientists able to grow the germs on a plate.

Doing battle with viruses is more complex ? in large part because of their simplicity. Viruses can range from one-fifth to one-100th the size of bacteria. And they are the ultimate parasite: They survive only if they hijack the cells of their victims; once inside, they begin churning out replicas of themselves.