Human H5N1 Bird Flu in China Raise Pandemic Concerns
Recombinomics Commentary, April 3, 2006

China has released three human H5N1 bird flu sequences. These sequences are similar to each other and most closely related to a duck isolate in Fujian Province. However, these isolates are quite distinct from other H5N1 sequences in China and elsewhere. Consequently, the pandemic vaccine in clinical trails around the world and the new vaccine target from Indonesia that was recently selected by the United States will not offer significant protection against these newly released sequences from China. Moreover, the vaccines under development will also offer little protection against the Qinghai strain which is linked to recent human outbreaks in Turkey, Iraq, Egypt, and Azaerbaijan.

Thus, at this time there are four distinct H5N1's causing fatal human infections which will likely require custom pandemic vaccines. Thus, as H5N1 evolves, the distance between vaccines under development and new versions of H5N1 cause human infections is increasing. In 2004 human cases in Vietnam and Thailand were linked to a similar H5N1. Last year Indonesia and China reported human cases and the recent release of sequence data clearly shows that the H5N1 in humans in Indonesia is quite distinct from H5N1 infecting humans in China and all three versions are distinct from the Qinghai strain of H5N1 causing human infections in the Middle East and Africa.