A leading scientist warned yesterday that the avian flu virus is on the point of mutating into a pandemic disease and says that current estimates that such a pandemic could cause 7.5m deaths may understate the threat.
His warnings come as experts writing in today's edition of Nature voice concerns about the world's inability to manufacture sufficient vaccines for a pandemic and warn of the impact that the virus - H5N1 - could have on the global economy.
In an accompanying editorial Nature argues that so far such warnings have "fallen on deaf ears". It backs a call by Prof Osterhaus and his colleagues at the Erasmus Medical Centre, in Rotterdam - one of the world's leading virus research labs - for a global taskforce to strengthen agencies on the ground.
There have been 90 human infections in south-east Asia , from which 54 people have died. But while culling and the vaccination of poultry appears to have slowed outbreaks in Thailand and other parts of south-east Asia, this year Vietnam has seen a worrying number of human infections in the same family groups. According to Prof Osterhaus such clustering could mean the virus is becoming more efficient at infecting humans - a precondition for a pandemic.
Another concern are reports which emerged from China last weekend that H5N1 was responsible for the deaths of 178 migratory geese at a wildfowl reserve in the western province of Qinghai earlier this month. Prof Osterhaus says the geese's deaths could be another indication that the virus is mutating and becoming more virulent. The problem is that countries such as China and Vietnam are not providing animal and human health officials with enough data, leaving scientists in the dark.
According to the WHO, within a few months of the pandemic 30 million people would need to be hospitalised, and a quarter could be expected to die. In his Nature commentary, Prof Osterhaus describes current estimates that a pandemic could infect 20% of the world's population and cause 7.5m deaths as "among the more optimistic predictions of how the next pandemic might unfold".
Such pandemic viruses emerge every 30 years or so. The most virulent was the 1918 Spanish flu pandemic, which is believed to have claimed 40 million lives worldwide. By contrast the 1957 Asian flu pandemic and 1968 Hong Kong flu claimed less than one million lives each. Prof Osterhaus wants the WHO, the UN Food and Agricultural Organisation and the World Organisation for Animal Health to set up global teams of vets, medics, virologists and agriculturalists to respond rapidly to outbreaks.
His comments are backed by the other experts in Nature, who also criticise the WHO and international efforts to develop vaccines against H5N1 and other strains of avian influenza.
According to Michael Osterholm of the University of Minnesota, antiquated vaccine manufacturing systems mean that countries like the US are unable to protect their populations against annual flu strains, let alone pandemic ones.
