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BY OUR PHARMA CORRESPONDENT
6 August, 2005: The two research papers published in the journals Science and Nature suggest that, under certain conditions, anti-viral drugs might contain, or even eliminate, an outbreak of human influenza.
An outbreak of influenza, in a pandemic proportion happen from time to time, researchers alert. Usually, the pandemic influenza is more deadly than the seasonal one as it is caused by the mutated virus.
Three such outbreaks occurred during the 20th century. The worst was in 1918, when one-quarter of the world's population fell ill and 25m-50m people died. The strain of avian influenza (bird flu) that is currently endemic in Asia has just the characteristics that keep epidemiologists awake at night. Recently, cases of bird flu have also been reported in birds (and also a person) in Russia and Kazakhstan.
It would take, in normal course, at least five months for virologists to produce vaccine in a large scale after identifying the virus. Some countries have started stockpiling vaccines against the strain of bird flu that is currently circulating, but there is no guarantee that this vaccine will convey enough protection against any human strain that might emerge.
Both the papers estimated the speed of influenza infection, the period till the carriers of the virus remain symptom-less and the number of secondary cases generated by a primary case in a susceptible population on the basis of what is known about previous pandemics.
The studies conclude that between 100,000 and 3m doses of anti-viral drugs would be needed to stamp out an outbreak, if deployed within three weeks of detection of the first case and combined with household quarantine. Where the virus is more transmissible or where the pandemic emerges simultaneously in many places, the number of doses needed would be at the top of this range. To prevent the spread of disease, anti-viral drugs would also have to be given to a high proportion of people in the surrounding area.
Countries like Australia, France, Hong Kong, Norway, Iceland, Luxembourg, Netherlands, Switzerland, Thailand, New Zealand, Singapore, United states, South Korea, Belgium,Canada, Denmark, Czech Republic,Finland, Britain etc have recently chosen to stockpile anti-viral drugs, primarily Tamiflu produced by Roche. Currently, as part of creating a global stockpile that could be delivered rapidly to the source of an outbreak, the World Health Organisation (WHO) is in advanced stages of negotiations with Roche. BY OUR PHARMA CORRESPONDENT
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