WHO: Global H5N1 vaccine stockpile may be feasible

Robert Roos

Apr 26, 2007 (CIDRAP News) – The World Health Organization (WHO) says nations and vaccine manufacturers agreed yesterday that it may be feasible to set up a world stockpile of H5N1 influenza vaccine and find a way to ensure that developing countries could access pandemic flu vaccine supplies.

Government officials and vaccine producers who met at WHO headquarters in Geneva agreed that "creating a stockpile of H5N1 vaccine, and separately developing a mechanism to ensure broader access to pandemic influenza vaccine for developing countries in the advent of a pandemic, may be feasible," the WHO said in a news release today.

"We have taken another crucial step forward in ensuring that all countries have access to the benefits of international influenza virus sharing and pandemic vaccine production," WHO Director-General Dr. Margaret Chan said.

Developing countries' access to pandemic flu vaccines emerged as a major international health issue in February, when Indonesia revealed it had stopped sending H5N1 virus samples to the WHO 2 months earlier. The government complained that drug companies would use its virus samples to make vaccines that Indonesia couldn't afford to buy.

After a Jakarta meeting in late March, Indonesia promised to resume sharing its virus samples immediately, in return for two WHO promises: not to turn viruses over to drug companies without the country's permission, and to prepare new virus-sharing guidelines. But Indonesia has not yet provided any more samples, according to news reports today.

The WHO said vaccine producers from developed and developing countries at yesterday's meeting expressed willingness to work with the WHO to pursue the possibility of an H5N1 vaccine stockpile and a mechanism to broaden access to pandemic vaccine.

The International Federation of Pharmaceutical Manufacturers and Associations, an industry organization, said it expects increased production capacity for seasonal flu vaccines to grow in the next 3 to 5 years, the WHO reported.

The WHO said it would now set up "expert groups to focus on the details of how to create, maintain, fund and use an H5N1 vaccine stockpile" and would continue to work with member states and other partners on the problem of access to pandemic vaccines.

The WHO statement didn't suggest how large a stockpile might be. But Dr. David Heymann, the WHO's assistant director-general for communicable diseases, said officials in developing countries have said they want enough vaccine to protect 1% of their populations, according to a Canadian Press (CP) report today.

"We have no idea what our official number will be. . . . But when asking what might be reasonable, one percent is what everybody is saying in the developing countries, that they would feel they need for essential populations," Heymann told CP.

As for where the vaccines for the stockpile would come from, Heymann said, "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."

Global flu vaccine production capacity remains very limited. Chan, in opening remarks prepared for yesterday's meeting, estimated the annual capacity at 500 million doses of trivalent (three-strain) vaccine, but other recent estimates have typically been lower, about 350 million trivalent doses. World population is more than 6 billion.

The WHO statement voiced optimism about the potential effectiveness of H5N1 vaccines now in development. The Strategic Advisory Group of Experts on Immunization concluded last week that recent studies of H5 vaccines showed them to be safe and immunogenic and that "it was realistic to expect that vaccines offering cross protection (against immunologically related but different viruses not contained in the vaccine) could be developed," the statement said.

Participants in the meeting agreed that all the efforts to provide pandemic flu vaccines must be based on the International Health Regulations as revised in 2005. The regulations, which take effect in June and have been adopted by most countries, are designed to prevent the international spread of diseases and limit the effects of other health emergencies, such as chemical spills.

In opening remarks at the WHO meeting, Director-General Chan said the threat of a flu pandemic is universal and requires global solidarity. "Public health security is a collective undertaking, a shared responsibility," she said, adding that all countries will be affected and all populations will be susceptible. Her speech was posted on the WHO Web site.

Chan, who is from Hong Kong, said further, "I believe that developing countries are right to ask us to address the issue of more equitable access [to vaccines] now. To date, developing countries have suffered the most from this virus."

She also observed that the course of the H5N1 avian flu problem has not been what experts expected back in early 2004, when the virus began spreading widely in Southeast Asia.

"Most experts expected one of two things to happen," she said. "Either a pandemic would start fairly quickly, especially since the virus was so widespread in animals, or the virus would attenuate. It would mutate into a form less deadly for poultry, and it would lose its ability to infect and kill humans.

"Neither has happened. Instead, this virus has given us a more protracted warning than anyone dared hope."

Meanwhile, Indonesia still has not resumed sending H5N1 virus samples to the WHO and has not offered a clear explanation for the delay, according to news reports today.

Reuters reported that Triono Soendoro, head of research and development for the Indonesian health ministry, said, "Last month's meeting resulted in a new mechanism and there are some administrative issues that need to be sorted out."

An Associated Press (AP) report said it was not clear what has caused the delay. It quoted Soendoro as saying Indonesia would resume sending samples when it has confidence that drug companies won't obtain the samples without Indonesia's approval.

WHO officials revealed last week that China had not shared any human H5N1 virus samples in about a year, though the Chinese did send some poultry samples of the virus last fall. After that revelation, Chinese officials promised they would resume sending human samples soon.

Scientists need samples of the virus to track its evolution and spread, look for signs of resistance to antiviral drugs, and develop vaccines.

Text of Dr. Margaret Chan's opening speech at the WHO meeting
http://www.who.int/dg/speeches/2007/250407/en/index.html

WHO description of the International Health Regulations
http://www.who.int/features/qa/39/en/index.html