"We would be wrong not to be developing stockpiles which can address a very crucial need at this point in time. And so we're doing whatever we can to make sure that this occurs," Dr. David Heymann, the WHO's senior representative for pandemic influenza, said from Geneva.
Just how large a stockpile might be and how quickly it might come together remains to be worked out, Heymann said.
"We have no idea what our official number will be. That's what we've been charged to do. But when asking what might be reasonable, one per cent is what everybody is saying in the developing countries, that they would feel they need for essential populations."
The comment followed a day-long summit called by WHO Director General Dr. Margaret Chan to look for ways to ensure that vaccine is not merely available to wealthy countries in the event of a pandemic. The meeting included WHO officials, executives of vaccine manufacturing companies and two industry associations as well as developing and donor countries.
Concerns about inequitable access to pandemic vaccine were brought to the fore earlier this year when Indonesia - the country hardest hit by the ongoing H5N1 avian flu outbreak - announced it would no longer share H5N1 viruses with WHO laboratories to protest the fact those viruses are used to make vaccines it cannot afford.
WHO collaborating laboratories need regular access to avian flu viruses to assess whether the virus is changing in ways that might increase the pandemic risk. And the WHO makes viruses available to pharmaceutical companies to make vaccines.
In an attempt to break that logjam, Heymann and other WHO senior officials travelled to Indonesia in late March for a meeting with countries affected by H5N1. Afterward, Indonesia said it would "immediately" resume sharing viruses - but to date it has not started shipping backlogged samples.
When the idea of a virtual vaccine stockpile was brought up there, a representative from Thailand raised the one per cent figure, saying his country would need enough vaccine to protect 600,000 essential workers - health-care workers, police and the military.
But deciding to set up a stockpile and setting a target of how much vaccine it should contain is only the first step in the process. The WHO would need to find countries or companies willing to donate from their own stockpiles or find funds with which to try to purchase vaccine from the limited global supply.
Heymann insisted parties at the meeting were open to exploring these possibilities.
"We believe that there will be a combination of donations from industry, possibly portions of national stockpiles would be made available from industrialized countries and funding," he said.
Over the next few weeks more work will be done on the idea, with staff hashing out how big a stockpile should be, under what circumstances it would be used and how it would be released to countries.
This work will form a "roadmap" that the WHO will present to member countries attending the annual meeting of the body's governing council, called the World Health Assembly, in late May, Heymann said.
