Washington

Ill-prepared: although flu vaccines are made every year, the world is not equipped to fight a pandemic. Credit: T. BOYLE/GETTY NEWS

Alarmed by bird flu's grip on southeast Asia, the World Health Organization (WHO) is calling for action. Last week, WHO officials met with vaccine makers, public-health experts and government representatives in a bid to speed up the production of flu vaccines to avert a global pandemic.

The three flu pandemics of last century — in 1918, 1957 and 1968 — were sparked when avian flu jumped the species barrier and became infectious in humans. The WHO has been warning for two years that conditions are right for a new pandemic — yet vaccines are still not available.

Theoretically, little stands in the way of preparing pandemic flu vaccines — the annual manufacture of vaccines for normal flu is routine. But companies and governments have been reluctant to invest in a vaccine that would never be used if the threat of a pandemic abates.

“The vaccines need to be tested, and that costs money,” said Klaus Stöhr, coordinator of the WHO's global influenza programme, at the 12 November meeting. “That is the single most important barrier to pandemic vaccine development.”

The strain of bird flu now circulating in Asia — known as H5N1 — has already killed 44 people this year, but does not seem able to spread from person to person, yet. WHO officials said at the meeting that the H5N1 strain seems to be increasing in virulence in chickens and mice, and may have found a reservoir in domestic ducks. The ducks can be infected for a lengthy period while appearing healthy, and could spread the disease back into poultry, and possibly humans, said WHO officials. The incubation of the virus in these different species may favour its evolution into a strain that can spread among humans.

But just two companies are currently testing a pandemic flu vaccine, and only a handful of countries have funded clinical trials of the vaccines. The WHO urged an acceleration of these efforts. “We can get our homework done now to ensure that when it matters most to get vaccines produced, it can happen immediately,” Stöhr said. “We don't want to miss this chance.”

Stöhr also noted the need to resolve inconsistencies in policies among international regulatory agencies, to avoid duplicating costly clinical trials (see Nature 432, 137; 200410.1038/432137b).

But the initiative still has challenges to face, said Stöhr. A major barrier is that patents on a crucial technology, called reverse genetics, are held by one company, MedImmune in Gaithersburg, Maryland. The technology has the potential to accelerate the process by which vaccines are selected and produced. Other companies hold associated patents. Representatives from industry told the meeting that dealing with patent issues has proved to be a major impediment for vaccine development in the past.

Some governments have begun to take action. The US National Institutes of Health is funding pandemic flu vaccine trials. The US health department also said on 9 November that it has issued a $10-million contract to secure a year-round supply of eggs needed to grow the volume of virus necessary for a pandemic flu vaccine. And Japan has expressed interest in funding trials, say WHO officials.

These efforts are admirable, but they are not enough, said Arlene King of Canada's Public Health Agency, who attended the Geneva meeting. “Pandemic influenza will be the biggest public-health emergency we ever face,” she said.