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H5N1 Wild Bird Flu In Humans In Indonesia?
Recombinomics Commentary
October 28, 2005
Recent investigations have indicated that H5 haemagglutinins (HA) genes of viruses from birds in China, Indonesia, Japan, Mongolia, Russia, South Korea and Turkey, and 3 viruses from humans in Indonesia are genetically distinguishable from the prototype strains selected last year for influenza pandemic vaccine development. There is also evidence of antigenic variation among the HA of recent viruses. However, their geographical spread and pathogenicity in human populations remain unclear.
The above commentary on the WHO pandemic vaccine effort suggests that the H5N1 wild bird flu that is geographically expanding its range may also be responsible for the sudden surge in human cases in Indonesia.
The H5N wild bird flu from Qinghai Lake clearly had homologies with H5N1 from Japan and South Korea. The H5N1 from Qinghai Lake was even more closely related to the H5N1 that expanded via migratory birds to Mongolia, Russia, and Turkey. The H5N1 wild bird sequences also have close homology to isolates from Romania and the timing and location of the outbreaks in China in Inner Mongolia, Anhui, and Hunan, would strongly suggest that the wild bird flu is responsible for those outbreaks also.
The inclusion of three viruses from humans in Indonesia suggests those isolates are also in the wild bird flu group, which would explain the increased concern about the human cases with bird flu symptoms in Hunan.
These data support a continued geographical expansion of H5N1 and creation of additional versions of H5N1 capable of causing fatal infections in human. The sequneces from these new 2005 outbreaks have not been made public. Release of this data would be useful.
The expansion of the pandemic vaccine effort into prototype vaccines for the additional genotypes is a welcome move. The wild bird flu is significantly different than the 2004 prototype in Vietnam, and it is expected to undergo further change via recombination with local versions of H5N1 as well as other serotypes which may be encountered for the first time as H5N1 migrates into new areas.
A significant increase in vaccine efforts is long overdue. As H5N1 migrates into new areas, the number of H5N1's capable of causing fatal human infections will increase via recombination with local influenza geneotypes.
New prototype vaccines are a start, but a major effort at creating regional specific vaccines base on anticipated recombination is necessary.
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