Bird-flu shot ready for trials
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Dennis Chong
The Standard
A vaccine for the deadly H5N1 virus is ready for testing on hu-
mans and is expected to be available in six months, the World
Health Organisation (WHO) said yesterday.
The United Nations health agency had said in January that a vac-
cine may not be available until next winter.
The new vaccine was developed by using a technology that in-
volves genetic modification of the virus.
Scientists said the vaccine can be easily modified to fight
other strains of bird flu.
"It has revolutionised the development of [flu] vaccine," Malik
Peiris of Hong Kong University's Department of Microbiology said
yesterday.
The technology, called reverse genetics, allows scientists to
engineer the virus in the laboratory by stitching together the
viral genes, before using them to mass-produce the vaccine.
"The technology shortened the time to develop a vaccine to a
matter of weeks," Robert Webster of the WHO's Collaborating
Laboratory on Influenza, who is also a visiting professor at the
department, said.
"Traditionally it can take two to three months to do that," he
said, adding that trials on humans will be initiated soon in the
United States and the vaccine may be ready for use in six
months.
"The safety of the vaccine in humans will be first tested in the
trial study," he said.
Webster said the vaccine was based on a strain found in Vietnam,
but it could be modified for other strains with the help of the
new technology. "We can make a change in the master strain very
very fast."
But Webster said since the deadly flu virus was genetically
modified, a method never used before to make flu vaccines, there
was always a risk involved.
"Some countries may not like the idea [of using genetically-
modified virus to make a vaccine], but we have to think of the
risks and the benefits."
Webster said the technology, in principle, can be applied to de-
velop a vaccine for Sars.
Health experts have warned that the deadly strain of bird flu
may mutate and affect Asia for years or even a decade. Webster
said the vaccine will be evaluated each year to ensure its ef-
fectiveness.
2 March 2004 / 02:00 AM