Discovery

It was written in NewScientist that for decades, hundreds of labs throughout the world have sent flu samples to the World Health Organization’s Global Influenza Surveillance Network, using a venerable test for similarity called haemagglutinin inhibition.

The analysis was objected to chart immunological changes in the virus that might signal a severe flu season, and to predict which strains will cause the next epidemic so as to put them in the annually updated flu vaccine.

With a huge database of flu viruses, Colin Russell and colleagues at Cambridge University took 13,000 viral samples from all over the world between 2002 and 2007, and mapped their immunological similarities.

He said that, new viruses appeared in eastern and southeast Asia 6 to 9 months before they showed up anywhere else, and took another 6 to 9 months to reach Latin America.

Co-author Derek Smith explained, the flu epidemic was related to season. When the climatic conditions are right in the northern or southern temperate zones, they strike a spark and seed the next winter epidemic.

Better surveillance in east Asia should lead to better predictions of how flu is evolving, and what is likely to be needed in next year’s flu vaccine, says Smith.

Journal references: NewScientist

Nature (DOI:10.1038/nature06945)