4 H5N1's causing fatal human infections

April 3, 2006

Commentary

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.

The spread of human H5N1 cases has also been associated with changes

in the receptor binding domain. The first reports were identified in

2003 isolates from a Hong Kong family that had visited Fujian

province. The H5N1 isolated from the patients contained S227N. This

change was subsequently found in human isolate(s) in Vietnam and most

recently in the index case in Turkey.

One of the isolates from China has a change at the adjacent position,

Q226R. Unlike the S227N change, Q226R has not been linked to

increased affinity for human receptors, although Q226L is the change

in human H3 HA that has been linked to increased affinity. Another

change, G228S ahs been predicted for Europe due to recombination

between Qinghai H5N1 and European swine H1N1.

In addition to these changes within the receptor binding domain,

changes near the receptor binding domain, (P185S, N186S, R193K) have

been recently reported in Iraq and China. These changes in and

around the receptor binding domain are cause for concern because

donor sequences are frequently found in flu from birds and the H5N1

host and geographical ranges are rapidly expanding.

The number of changes is also not know because many of the recent

human isolates have been sequestered in a private WHO database. The

human H5N1 sequences from Iraq, Indonesia, and China have been

released in the past few weeks. However, human sequences from

Turkey, Azerbaijan., Egypt and additional sequences from China and

Indonesia have not been released, so additional polymorphisms linked

to the receptor binding domain may have already entered the reservoir

of human H5N1 infections.

H5N1 is clearly rapidly evolving via recombination, as efforts to

address these genetic changes continue to lag.

http://www.recombinomics.com/News/04030603/H5N1_China_Pandemic.html

April 3, 2006

so what exactly does this mean now. since there are 4 seperate strains,

does the chance of one mutating/recombining increase x 4??

Lee wrote:

>Commentary

>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.

>

>The spread of human H5N1 cases has also been associated with changes

>in the receptor binding domain. The first reports were identified in

>2003 isolates from a Hong Kong family that had visited Fujian

>province. The H5N1 isolated from the patients contained S227N. This

>change was subsequently found in human isolate(s) in Vietnam and most

>recently in the index case in Turkey.

>

>One of the isolates from China has a change at the adjacent position,

>Q226R. Unlike the S227N change, Q226R has not been linked to

>increased affinity for human receptors, although Q226L is the change

>in human H3 HA that has been linked to increased affinity. Another

>change, G228S ahs been predicted for Europe due to recombination

>between Qinghai H5N1 and European swine H1N1.

>

>In addition to these changes within the receptor binding domain,

>changes near the receptor binding domain, (P185S, N186S, R193K) have

>been recently reported in Iraq and China. These changes in and

>around the receptor binding domain are cause for concern because

>donor sequences are frequently found in flu from birds and the H5N1

>host and geographical ranges are rapidly expanding.

>

>The number of changes is also not know because many of the recent

>human isolates have been sequestered in a private WHO database. The

>human H5N1 sequences from Iraq, Indonesia, and China have been

>released in the past few weeks. However, human sequences from

>Turkey, Azerbaijan., Egypt and additional sequences from China and

>Indonesia have not been released, so additional polymorphisms linked

>to the receptor binding domain may have already entered the reservoir

>of human H5N1 infections.

>

>H5N1 is clearly rapidly evolving via recombination, as efforts to

>address these genetic changes continue to lag.

>http://www.recombinomics.com/News/04030603/H5N1_China_Pandemic.html

>

April 3, 2006

Not necessarily. It's like the hepatitis c virus, kind of, which has many different mutations which we call genotypes. That's why they can't make a vaccine against hepatitis C, which is a RNA retro virus. They mutate easily, while DNA viruses do not. I'm not sure if H5N1 is DNA or RNA, although I suspect it's DNA. Does anyone know for sure? Colleen Elke <avalon@...> wrote: so what exactly does this mean now. since there are 4 seperate strains, does the chance of one mutating/recombining increase x 4??Lee wrote:>Commentary>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.>>The spread of human H5N1 cases has also been associated with changes >in the receptor binding domain. The first reports were identified in >2003 isolates from a Hong Kong family that had visited Fujian >province. The H5N1 isolated from the patients contained S227N. This >change was subsequently found in human isolate(s) in Vietnam and most >recently in the index case in Turkey.>>One of the isolates from China has a change at the

adjacent position, >Q226R. Unlike the S227N change, Q226R has not been linked to >increased affinity for human receptors, although Q226L is the change >in human H3 HA that has been linked to increased affinity. Another >change, G228S ahs been predicted for Europe due to recombination >between Qinghai H5N1 and European swine H1N1.>>In addition to these changes within the receptor binding domain, >changes near the receptor binding domain, (P185S, N186S, R193K) have >been recently reported in Iraq and China. These changes in and >around the receptor binding domain are cause for concern because >donor sequences are frequently found in flu from birds and the H5N1 >host and geographical ranges are rapidly expanding.>>The number of changes is also not know because many of the recent >human isolates have been sequestered in a private WHO database. The

>human H5N1 sequences from Iraq, Indonesia, and China have been >released in the past few weeks. However, human sequences from >Turkey, Azerbaijan., Egypt and additional sequences from China and >Indonesia have not been released, so additional polymorphisms linked >to the receptor binding domain may have already entered the reservoir >of human H5N1 infections.>>H5N1 is clearly rapidly evolving via recombination, as efforts to >address these genetic changes continue to lag.>http://www.recombinomics.com/News/04030603/H5N1_China_Pandemic.html>>>>>> >

April 3, 2006

Hi ,

dr. Niman is participating in discussion on the avian flu forum. he

commented that 1 one of those strains would likely appear in birds here

in the us. the other 3 via plane.

check itout

http://www.avianfluforum.com