Re: Pandemic Flu - Thread II
Commentary by Dr. Niman on the viral sequence data released on the recent
H5N1 case in Egypt. It is of a predictive nature, and indicative of the possibility of this virus becoming more easily transmissible.
http://www.recombinomics.com/News/10...5N1_M230I.html Originally Posted by www.recombinomics.com/News/10220603/H5N1_M230I.html ... the sequence also has an alteration, M230I, near the receptor binding domain.
Changes in the receptor binding domain are cause for concern because they can alter the ease of transmission...
Changes in the receptor binding domain in the Qinghai strain are of additional concern because the Qinghai strain has already acquired a mammalian polymorphism, PB2 E627K. This change increases polymerase activity at lower temperatures. It offers strong selective advantage...
... additional changes in or near the receptor binding domain of Qinghai isolates are cause for concern... H5N1 in Egypt may be further spread by migratory birds.
The change in the cleavage site has been reported in H5N2 birds from Mexico, as well as H5N1 from Vietnam. Recombination between Clade 1 H5N1 in Vietnam and Clade 2 Qinghai H5N1 provides a mechanism for further genetic diversity in the Qinghai strain. The Egypt isolates also have polymorphisms found in human H5N1 isolates in in Indonesia.
The Qinghia strain is associated with increased virulence in both birds and mammals.
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