Vietnam Pledges Not to Pursue Human Vaccine for Bird Flu on Its Own
Saturday, May 28, 2005
JAKARTA, Indonesia, May 27 -- Vietnam has promised it will not unilaterally develop a human vaccine for bird flu, abandoning plans that international health experts had complained were hazardous and could themselves trigger an epidemic, the World Health Organization said Friday.
Instead, Vietnamese officials agreed they would use a prototype virus strain provided by WHO and developed under safe conditions, according to Klaus Stohr, chief of the agency's global influenza program.
Stohr said his agency had been prepared to raise formal objections with the Health Ministry in Hanoi after the head of the vaccine development project told The Washington Post that Vietnam was determined to develop a vaccine on its own.
The comments by Prof. Nguyen Thu Van, including the disclosure of plans to hold human trials by August, contradicted guarantees from Vietnamese officials that they would call off the endeavor, WHO officials said.
WHO researchers expressed concerns that material used to produce the vaccine strain could be contaminated by other viruses and that a breach of security in the laboratory could allow a more dangerous version of the bird flu virus to escape.
The health attache at the U.S. Embassy in Hanoi raised concerns this week about Van's comments with the director of her institute, the National Institute for Hygiene and Epidemiology, WHO officials said. The director repeated assurances that Vietnam would not proceed with its homegrown vaccine program.
When Stohr learned of the new guarantee, he said he decided to hold off on a letter insisting that Vietnam adhere to its commitment.
"We want to make sure the position of WHO is crystal clear so there are no surprises later on," Stohr said, explaining the letter he had been drafting about Vietnam's program. "It does not fulfill the conditions for safety for vaccine development."
Stohr said WHO is proceeding with plans to supply Vietnam with a prototype strain and material for standardizing and testing the virus vaccine.
International health experts have highlighted several concerns about Vietnam's program to develop a human vaccine for bird flu, which has already killed at least 54 people in Southeast Asia, including 37 in Vietnam. These experts said people could become infected with other viruses inadvertently carried in the vaccine.
More ominously, the process for developing the experimental vaccine stock, which was grown in the cells of monkey kidneys, could have allowed the bird flu virus to mutate, making the vaccine strain even more deadly and easier to pass among humans, experts said. In producing the vaccine, they said, the researchers might accidentally become exposed or otherwise release the virus.
WHO officials have also pressed concerns about Vietnam's plans to conduct human trials, starting with Van and some of her team as subjects, as well as about security at the labs used to produce the vaccine.
In an interview last month at her institute, Van said she did not share these worries about the safety of her program. "I believe in our procedures and all the laboratory testing. I'm sure our vaccine is safe, so I'm not concerned," she said.
She said Vietnam had decided not to wait for international assistance because it needed to be sure it had access to an affordable bird flu vaccine. Van said she was confident of her initiative because of her success in developing a hepatitis B vaccine.