Race to curb mutating virus

2005-10-14 12:28

Paris - As bird flu arrives at the gates of Europe the race is on around the world to find a vaccine to treat a possible pandemic, but nobody knows what form the virus may eventually take and manufacturing capacity is desperately scarce.

The problem is that the avian flu virus H5N1, the most likely to lead to human-to-human infection - a much more dangerous scenario - complicates the quest by continually mutating.

A prototype vaccine developed from the strain identified in 2003 has had to be abandoned because it is no longer of use against the form the virus discovered the following year, according to the World Health Organisation (WHO).

But from Vietnam to Chicago teams of researchers continue to work on "drafts" of the vaccine with the aim of winning valuable time if the virus does show up in a "humanised" form.

The Sanofi Pasteur laboratory has concluded a deal worth $100m to produce "between the start of September and the end of October" this kind of "pre-pandemic" vaccine, after having already produced several million doses ordered by, among others, France and the United States. Clinical trials are under way.

US researchers say they have come one step closer to developing a tougher, more flexible bird flu vaccine that could be produced significantly faster than traditional vaccines and would also protect against future viral mutations.

The vaccine would be delivered by a harmless virus that could be developed in tissue cultures rather than chicken eggs.

This would guard against concern that eggs could become scarce during a pandemic and also allows for significantly faster and larger production cycles, said lead researcher Suresh Mittal at Purdue University in Indiana.

'It is a race against time'

It could be produced within two months after the identification of the strain rather than the usual six months, Mittal said.

Hungary will know within a fortnight whether human trials of a bird flu vaccine have been successful, opening the way to mass production.

Health Minister Jeno Racz said on Tuesday that if the results were positive, up to half a million doses could be produced weekly within three months.

Racz himself is one of 150 guinea pigs in experiments that started last month to find a way to tackle the H5N1 virus.

Research is also underway in Germany and Vietnam.

The H5N1 avian flu virus has been found mainly in 10 southeast Asian countries and has so far infected 112 people, of whom 60 have died, according to the World Health Organisation.

So far it has only spread from birds to humans, but health officials warn that human-to-human infection may not be far off.

It is a race against time. The world will have a "brief intervention window" of between six and 10 months between the emergence of a pandemic virus and its spread worldwide, according to WHO expert Klaus Stoehr last year.

- AFP