Post by Shadow on Dec 18, 2005 13:21:40 GMT -5
Tests dash hopes of rapid production of bird flu vaccine
New Scientist
# 17:43 16 December 2005
# NewScientist.com news service
# Debora MacKenzie
The results of first large-scale trials of a low-dose vaccine against H5N1 bird flu have been announced – and they are unexpectedly disappointing. Scientists had hoped that very low doses of vaccine virus would make humans immune if injected along with an immune-stimulating chemical called an adjuvant.
But on Thursday, French vaccine company Sanofi pasteur announced that in tests on 300 people in France, they did not. “The prospects for adequate global supplies of an effective pandemic vaccine of any kind are dimmer now than they were last week,” David Fedson, founder of the vaccine industry’s pandemic task force, told New Scientist.
The first tests of H5N1 vaccine in the US in August 2005 found that the virus on its own does not stimulate much immunity in people. To elicit enough to ward off disease, a vaccine required 90 micrograms of the virus’s main surface protein - six times more than is needed in ordinary flu vaccine.
The less virus is required per dose of vaccine, the more doses vaccine factories can produce in the limited time that will be available to immunise people at the start of a pandemic. Research with other types of bird flu have found such low-dose vaccines are possible, if the virus is combined with an adjuvant.
New Scientist
# 17:43 16 December 2005
# NewScientist.com news service
# Debora MacKenzie
The results of first large-scale trials of a low-dose vaccine against H5N1 bird flu have been announced – and they are unexpectedly disappointing. Scientists had hoped that very low doses of vaccine virus would make humans immune if injected along with an immune-stimulating chemical called an adjuvant.
But on Thursday, French vaccine company Sanofi pasteur announced that in tests on 300 people in France, they did not. “The prospects for adequate global supplies of an effective pandemic vaccine of any kind are dimmer now than they were last week,” David Fedson, founder of the vaccine industry’s pandemic task force, told New Scientist.
The first tests of H5N1 vaccine in the US in August 2005 found that the virus on its own does not stimulate much immunity in people. To elicit enough to ward off disease, a vaccine required 90 micrograms of the virus’s main surface protein - six times more than is needed in ordinary flu vaccine.
The less virus is required per dose of vaccine, the more doses vaccine factories can produce in the limited time that will be available to immunise people at the start of a pandemic. Research with other types of bird flu have found such low-dose vaccines are possible, if the virus is combined with an adjuvant.