H5N1 genetic changes

[Guest guest]

Recombinomics Predicts a New Genetic Change in Avian Flu Virus

2/21/2006

 

Recombinomics issued a new prediction and warning of a likely

alteration in the avian influenza H5N1 hemagglutinin gene. This

alteration will increase the virus' affinity for human receptors and

lead to more efficient transmission of H5N1 to humans, notes the

firm.

 

A separate Recombinomics' warning, made in October, was based upon

H5N1 entering the Middle East via migratory birds, where another

avian influenza, H9N2 was endemic. Recombinomics predicted that the

H gene in H5N1 would exchange genetic information with the H gene in

H9N2 and would acquire the genetic change S227N (also called S223N).

This alteration had been previously shown to increase the affinity

of H5N1 for human receptors.

 

In late December, the first human infections by the Qinghai strain

of H5N1 were reported in Turkey. S227N was detected in the index

case for that outbreak with six additional cases confirmed.

 

Recombinomics is predicting a similar change in the adjacent

position of the H5N1 virus' receptor binding domain. The donor

sequences are again on the H, but in H1N1 European swine sequences.

The new genetic change, G228S, has also been previously shown to

increase the affinity for human receptors. Like H9N2 in the Middle

East, H1N1 is endemic in swine populations in Europe. Infection by

H5N1 in H1N1 infected swine will allow the viruses to exchange

genetic information via recombination and allow H5N1 to acquire

S228N. The region of identity between H5N1 and H1N1 is downstream

from the S227N position, so H5N1, with and without the S227N change,

can acquire this new sequence. This sequence acquisition by the H5N1

virus will also lead to more efficient transmission to humans.

 

" H5N1 is migrating into areas where it is encountering unique

influenza serotypes it has not encountered while largely confined to

Asia over the past few years. This expanded geographical reach

allows H5N1 to exchange genetic material with novel donor sequences,

which under the appropriate selection pressures, enables the genetic

changes to become fixed in the genome of the virus. H5N1 is in the

process of acquiring genetic information that allows for more

efficient infections of humans, " says Recombinomics president, Henry

Niman, Ph.D.

 

 

In short, the ability of H5N1 to mutate into a highly virulent

deadly virus with an ability to transmit human to human is

increasing rapidly. I feel we will see more and more human cases in

the comming weeks as well as it's arrival in the US. Maybe not in

H2H form yet, but I don't think iit will be long. Just a heads up.