By Rachael Buchanan
World health officials seem in little doubt that we stand on the verge of another influenza pandemic.
Science can come up with some defences
Experts believe it highly likely that a bird flu virus will soon mix with a human or pig virus and pass from human to human.
"We are getting closer, but when it's going to happen, I don't know," Francois Xavier-Meslin, the World Health Organization's coordinator for disease control, prevention and eradication, said this week.
He was speaking at a task force meeting on bird flu led by the Association of Southeast Asian Nations.
The gathering comes just days after the UK government announced how it would react in the face of a flu pandemic and the WHO itself showed off its new "nerve centre" for public health emergencies.
On the face of it the world is gearing up for what seems inevitable - the sudden emergence of a highly infectious, novel strain of influenza that would spread through our communities like wildfire because we have no immunity.
But are state of the art communication centres and paper projections for school closures enough if governments are not investing in the science and the drugs to back it all up? The world's flu experts think not.
In the journal Nature, researchers from Harvard warned that failure to finance effective medication would mean draconian quarantine measures and movement control would be our only hope of containing an outbreak.
They are echoing concerns already expressed by leading UK flu expert John Oxford, of Queen Mary's College, London.
He believes we have never been so close to a global outbreak and yet warns that without pharmacological foundation, the British government's pandemic plan is little more than "the Emperor's new clothes".
Oxford has recently shown that one antiviral in particular - oseltamivir (Tamiflu) - will work to block all the known types of flu. This includes the strain scientists fear could be the one to trigger a pandemic, H5N1.
The strain has already killed 32 people in Vietnam and Thailand since the end of 2003.
Antivirals can be effective. They work by blocking the neuraminidase protein, a spike on the outside shell of a flu virus that helps it break out of our cells and so spread new virus particles throughout the body.
But they are not a magic bullet. Antivirals do not give immunity like vaccines, so you have to keep taking them.
Antivirals are not being stockpiled
Until vaccines can be developed and mass produced, Oxford argues, they will be our first and our only line of defence. So far, only a couple of countries, such as Australia and Japan, have stocked up.
He recently went to meet Members of the European Parliament (MEPs) to try to persuade them that European governments needed to be more proactive - and he is frustrated at the lack of movement.
"There is a drug sitting there in minute quantities in pharmacies, which could be used to help ameliorate this virus spreading in the community," Professor Oxford told BBC News.
"So it seems like not clear thinking to me; it seems like not taking any decision.
"When you know the stuff works, why aren't you stockpiling it in anticipation of an outbreak so you can protect the citizens of your own country?"
Of course vaccines are the gold standard in flu protection. But flu strains mutate (undergo genetic changes) quickly, so science is constantly running to keep up.
What matters are two proteins - the neuraminidase (N) and haemagglutinin (H), also found on the virus' outer shell.
They help it infect cells, reproduce and then spread. We are used to certain strains such as H1N1 and H3N2 and have a certain amount of immunity to them. We already have vaccines.
What turns flu from an annual annoyance to a global killer is when one or both of the shell proteins mutate. Then we have neither immunity nor a vaccine to fight it.
So far, the current avian flu strain circulating in Southeast Asia has not learnt how to pass from human to human. Each victim has caught it from chickens, and the victim has become a viral "dead end".
So the world plays a waiting game, pending the emergence of a type with the virulence of chicken flu and the transmissibility of human flu.
Then it will take precious months to develop and produce a viable vaccine in sufficient quantities - and who knows how many might die in the meantime?
Some researchers are not going to wait. Earlier this year, the UK's National Institute for Biological Standards and Control (NIBSC) in Hertfordshire and the St Jude's Children's Hospital in Memphis, US, tried to get ahead of Nature.
Time and cost
They took the Vietnam H5N1 strain and a harmless human influenza virus and genetically engineered combinations - strains that would look to the immune system like a humanly transmissible avian flu.
The pathogenic sections were snipped out to make them safe to handle and samples were delivered to the WHO in the spring. Now it is up to the vaccine companies and governments to devise the pharmaceutical containment that would protect the public if "wild" types emerged.
But developing an experimental vaccine costs millions of dollars, and so far only the US government has stuck its hand in it pocket.
This summer, it awarded pharma company Aventis Pasteur a $13m contract to provide two million doses from the "St Jude's strain".
Any new pandemic is likely to originate in Asia, experts say
But what of Europe? At Aventis Pasteur's research centre near Lyon, France, they are quietly working on the NIBSC strain, but on a much smaller scale, producing just a few thousand doses which will all be used up in clinical trials.
This work is purely speculative - no European government has put in an order and if a pandemic strain emerged tomorrow, we would be defenceless.
But Aventis sees this as "a dress rehearsal, to understand the pitfalls, so, when the real time comes, we have learned from our past lessons and are ready to go", says Marie-Jose Quentin-Millet, their head of research at the Lyon site.
But even if the geneticists' best guesses turn out to be on the money, producing just one batch of vaccine takes several months.
Klaus Stohr, head of the WHO's influenza programme, has predicted a pandemic virus could sweep through Europe in a matter of weeks. By the time enough vaccine is produced, millions could be infected or even dead.
We have a window of opportunity, warns John Oxford, and governments need to invest in drugs now.
"I am giving them a public health warning," he said. "Vaccines and antivirals are simply health insurance for our communities".