Tuesday, March 06, 2007

March 5 Flu Update

Helen Branswell on the big vaccine news, that GSK says it has a vaccine that protects against multiple strains of bird flu.

The GSK vaccine is made with an adjuvant, a chemical that significantly enhances the activity of the vaccine. Earlier work by the company showed it could trigger what is thought to be a protective response with two small doses of vaccine, at 3.8 micrograms apiece.

An unadjuvanted vaccine made by Sanofi Pasteur required more than 23 times as much antigen - two doses of 90 micrograms - and even then fewer than half of volunteers generated antibody levels thought to be protective.

(Given this, can someone with a better background explain to me why the US is using the Sanofi vaccine?) Revere blogs on the Sanofi vaccine being "better than nothing."

China is the source of H5N1, according to this analysis. More specifically, Guangdong.\

And Guangdong appears to be the source of renewed waves of the H5N1 strain, which has killed or forced the destruction of hundreds of millions of birds, the team at the University of California Irvine reported.

"We show that the Chinese province of Guangdong is the source of multiple H5N1 strains spreading at both regional and international scales," the researchers wrote...


Russia says that new cases have stopped emerging in birds.

China is gearing up to fight the flu, including required immunization of all domestic poultry.

There were dead birds in Myanmar, but they do not have H5N1, according to reports.

There are now 50 avian cases of flu in Kuwait.

25,000 birds have been culled in Kuwait.

Reports from Laos continue to indicate that the country had its first bird flu death.

WHO concurs, via CIDRAP.

Africans are reminded that bird flu remains a threat.

Business Week on the leverage Indonesia has won for poor countries in the struggle to allocate flu resources.

A Canadian professor outlines the threats of bird flu for a Romanian publication.

A table top exercise will be held in Saipan.

A couple of days ago, we ran a story about a vaccine solution proposed in Hong Kong. This is a profile of the researcher, who is using techniques he learned fighting AIDS.

A Health Region in Alberta is holding a pandemic seminar.

Malaysia says it is sharing its experience in diagnosing flu with other countries, since they are bird flu free and all.

The UAE is stockpiling Tamiflu to prepare for a bird flu pandemic.

1 Comments:

At 9:04 PM, Blogger Wulfgang said...

Orange;

Very nice set of articles today. The crème of the crop.

I’d like to zero in on the big vaccine news by GSK, reported by Helen Branswell, and at the same time, tie in the China “Guangdong and Qinghai” province connections, which serve as primary avian influenza virus “epicenters” for that entire Asian region . For several days now, I have been commenting about a total of at least eight China provinces in all, which cut a diagonal swathe clear across the southern and western regions of the country, where H5N1 is now endemic and firmly embedded in the poultry and populations. Xinjiang, Sichuan, Yunnan, Hunan, Fujian, and Anhui are the other six provinces not named. The National Academy of Sciences study and the article you posted still does not reveal the dire situation in China. In fact, today in the headlines, H5N1 was reported also in Tibet, which borders the Xinjiang, Qinghai, Yunnan and Sichuan provinces, and is adjacent to Myanmar. This is not a coincidence.

Nobody should be surprised this is happening. Avian influenza viruses type A, from China, are the source of genes that reassorted with human viral genes, which evolved into and caused the pandemics of 1957 (H2N2) and 1968 (H3N2). In fact, both pandemic viruses originated from avian viruses and spread like wildfire after reassortment with common human influenza strains. Swine was most likely the mixing vessel.

Professor Guan Yi of Hong Kong University states, “Updated virological and epidemiological findings from our market surveillance in southern China demonstrate that H5N1 influenza viruses continued to be panzootic in different types of poultry”. He is quite correct, and the situation is actually a little worse than even he is stating:

• Serological studies indicate that the H9N2 and H7N7 avian viruses have infected a very large number of domestic poultry in most of the southern Chinese provinces I mentioned. They are evolving just as rapidly as H5N1, and are in the process of adapting to new hosts. Both internal genes are closely related to H5N1 and both also have the potential to infect humans as a potential pandemic virus.
• The H6N1 has also been found circulating in China poultry in several of these provinces. The H9N2 I just mentioned, the H6N1 and the H5N1 subtypes of avian influenza viruses, all are perfectly capable of exchanging internal genes. This process could generate a potential pandemic hybrid virus.
• The H9N2 and H5N1 influenza viruses are prevalent all year round in China poultry, and both subtypes have exchanged gene segments with circulating reassorted subtypes, that could also generate a new unknown type A pandemic virus. It is believed that they both replicate asymptomatically in poultry, due to vaccinations.
• The H7N7 influenza virus has been identified in human beings in southern China.

As your Guangdong article alludes to, but doesn’t mention, not only is H5N1 originating in the Guangdong and Qinghai provinces, and spreading, but numerous other avian influenza virus strains are also percolating, recycling and spreading from these epicenters also. Co-infection of any of these Type A avian influenza viruses I mentioned above, with humans during normal influenza activity of common H3N2, or H1N1 viruses, or with swine, could result in any number of novel hybrid pandemic viruses. So, in my view, the situation is much graver than most people think, and I believe countries like Thailand, Tibet, Cambodia, Laos, Malaysia, Vietnam and Indonesia are not only absorbing H5N1 strains, but are already beginning to absorb some of the other avian strains as well, and don’t know it yet.

While the GSK bird flu vaccine with its proprietary adjuvant, appears on the surface to look promising towards protecting against a variety of H5N1 strains, it may prove absolutely useless against any of the other novel mutations possibilities I have mentioned. Of course, the H5N1 is the most predominant of the emerging and diffused avian influenza strains, versus all the others currently circulating in China, therefore it would appear to be the best bet for a leading vaccine. But creating a vaccine is educated guesswork.

It has been nearly four decades since we have had a pandemic, and the clock is ticking. There is no other way to describe the avian influenza virus situation in China, other than to say it is out of control. It has been out of control there since May 1997, when a 3 year old boy in Hong Kong died due to ARDS and scientists spotted H5N1 in his organs. It was still out of control in July 2005, when 27 farmers in the Sichuan province mysteriously died due to “streptococcus suis”, when it really sounded more like avian influenza. Note that just prior to their deaths, in April-June 2005, over 10,000 birds died in the Sichuan, Qinghai and Hinjiang provinces.

Because of the density of humans packed into to the Asian and China geographical area, I believe the only way to even attempt to temporarily contain a pandemic, and give the rest of the world enough warning, will be swiftly quarantining all suspected human cases and closing all borders and air travel, when the time arrives.

I never exaggerate. I just remember big.

Wulfgang

 

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