Bird flu virus - most lethal flu virus ever - still major concern: WHO

[Giuseppe]

Reuters AlertNet - Bird flu virus still cause for concern - experts

Bird flu virus still cause for concern - experts
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[Concerns? Yes. It's worrying... But why do these researchers not try to explain to us how they intend to cope with a such massive events with oseltamivir alone or with few doses of a pre-pandemic vaccine? And some words about H1N1-oseltamivir-resistant strain massive spread around the world - and the partially mismatched trivalent seasonal vaccine would be welcomed. IOH]

03 Feb 2009 20:23:23 GMT
Source: Reuters
By Maggie Fox, Health and Science Editor
WASHINGTON, Feb 3 (Reuters) -

The H5N1 bird flu virus, which has now sickened more than 400 people globally, is infecting birds and people all across China and is still a cause for serious concern, flu experts said on Tuesday.


Recent cases are the expected winter seasonal surge seen for many types of viruses, they said, and there is no evidence that it is mutating into a more dangerous form.

"In the past three months, we have continued to see a great deal of activity," Dr. Keiji Fukuda of the World Health Organization told reporters.

Chinese officials confirmed a new case on Monday in a 23-year-old woman in Hunan province, who was being treated.

All the patients were around chickens, so there is little concern that people are passing the virus to one anther, the flu experts told a news briefing at a meeting in Washington of the Infectious Diseases Society of America.

"These cases and the widespread nature of them continue to point out how persistent this virus is and how widespread it is," Fukuda said. "We believe that the threat of pandemic influenza remains as high as ever."

Since 2003, the H5N1 avian influenza virus has infected 404 people in 15 countries and killed 254 of them. It has killed or forced the destruction of more than 300 million birds as it spread to 61 countries in Asia, the Middle East, Europe and Africa.

"This is a very unusual virus and the reason why it so unusual is that it is probably the most lethal influenza virus that has ever been discovered," Fukuda said.

AMAZING ABILITY TO KILL
"It really has an amazing ability to kill a variety of birds and mammals, including people."

Fukuda said China had investigated each case thoroughly, and he did not see any especially worrying signs in the eight recent cases.

"It has been noticed that the people who have been infected are spread across a wide area of China. What that tells us is that the virus is widespread in China. But we have known for a long time that it is widespread in Southeast Asia in general," he said.

It is also known that vaccinating birds against H5N1 is not 100 percent effective, so it is not surprising that individual birds would become infected and spread the virus to people, he said.

While H5N1 rarely infects people, experts fear it could mutate into a form that people could easily pass to one another, sparking a pandemic that could kill tens of millions and topple the global economy.

Dr. Nancy Cox of the U.S. Centers for Disease Control and Prevention said while the virus is mutating steadily, it is not taking on any startling changes yet.

"We have not seen changes in the genes of H5N1 viruses that would be indicative of the kind of change that we would expect were the virus to become more transmissible from human to human," she said.

Fukuda and other experts praised China for being so quick to report and investigate each case.

"Hopefully, we will see this become the standard behavior for most countries," Fukuda said.

Experts say the odds of an influenza pandemic of some sort are 100 percent. No one can say when or where it might happen, or what strain of flu might cause it, and Fukuda noted that H5N1 is not the only threat.

(Editing by Will Dunham)
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<cite cite="http://www.alertnet.org/thenews/newsdesk/N03538636.htm">Reuters AlertNet - Bird flu virus still cause for concern - experts</cite>

 

[Shiloh]

Bird flu virus - most lethal flu virus ever - still major concern: WHO

Source: http://www.google.com/hostednews/canadianpress/article/ALeqM5j1yPxJsUGkH-BkE6MYEo9buoCh8g

Bird flu virus - most lethal flu virus ever - still major concern: WHO

TORONTO ? The danger posed by H5N1 avian flu specifically and a flu pandemic in general may no longer dominate news headlines but it has not subsided, experts warned Tuesday at an international scientific conference on influenza.

"The story has gone away, but the threat hasn't," Dr. Andrew Pavia, head of the Infectious Diseases Society of America pandemic influenza task force, said in a teleconference for journalists from Washington, D.C.

The head of the World Health Organization's global influenza program concurred, urging governments and organizations to persevere in efforts to prepare for a future flu pandemic, calling that work "a high public health priority."

"In the assessment of WHO, we believe that the threat of pandemic influenza remains as high as ever," said Dr. Keiji Fukuda, who suggested the recent surge in human H5N1 cases - eight of which have been reported by China - underscores the ongoing problem.

He said the individual Chinese cases have been investigated and WHO believes they represent bird-to-human transmission, not the person-to-person spread that could signal the start of a pandemic.

However, Fukuda said it was "noticeable" that the cases have cropped up in diverse parts of China. "And what that really tells us again is that the virus is really widespread in China," he said.

China is not alone in that reality. Recent human cases have also been reported by Indonesia, Vietnam and Egypt. And the virus is known to be endemic in bird flocks throughout much of Southeast Asia, the Indian subcontinent and parts of Africa as well.

But experts have raised concerns about the fact that cases in China have often occurred in places where there have been no previously reported outbreaks in birds. That suggests surveillance systems are either missing outbreaks or that word of them isn't being pushed all the way up the reporting chain.

Experts are also dismayed by the evidence that the virus is continuing to spread despite massive efforts by Chinese authorities to vaccinate poultry flocks across the country.

Fukuda said, though, that it is not unexpected to see occasional cases, particularly at a time of year when an upswing in infections has historically been noted.

"The vaccine coverage is not perfect. It's clear that not every bird in every country gets vaccinated. And it's also clear that there are certain kinds of birds like ducks and geese which don't respond to vaccine but which easily get infected by these H5 viruses," he said.

"So when you put that all in the mix, I think that it's not surprising that we will see individual cases occurring in countries even with high vaccination coverage rates."

Fukuda praised China's efforts, noting the country has reported its recent human cases promptly - a welcome trend.

"Hopefully we will see this become just a standard of behaviour for all countries," he said. "Anyway, it's very nice."

Fukuda did not name countries which aren't reporting as quickly as China.

But Indonesia, which has had more cases of H5N1 than any other country, is currently following a policy of only publicly reporting human infections from time to time rather than as they occur.

The country has been locked in a dispute with the WHO and other countries over the sharing of virus samples for the past two years. Health Minister Siti Fadilah Supari has insisted Indonesia will not share virus samples unless it receives assurances it will receive a supply of any vaccine made from the viruses.

China, which was pilloried internationally for trying to cover up the emergence of Severe Acute Respiratory Syndrome or SARS in 2003, did not always report its H5N1 cases rapidly either. But of late authorities have been alerting the international community within days of confirming new cases.

"I think China has had its fair share of experience with these emerging infectious diseases and I think in general they have made huge strides," Fukuda said.

But he suggested surveillance for H5N1 outbreaks still needs to improve.

"We need to be able to have more information on cases, both human cases and animal cases. And so I think it just points out that there's more work to be done in this area."

 

[Giuseppe]

Re: Bird flu virus - most lethal flu virus ever - still major concern: WHO

CIDRAP >> Experts weigh new H5N1 vaccine strategies

Experts weigh new H5N1 vaccine strategies

Lisa Schnirring * Staff Writer
Feb 3, 2009 (CIDRAP News) ?

At an Infectious Diseases Society of America (IDSA) symposium in Washington, DC, today on seasonal and pandemic influenza, a group of experts fielded questions from reporters on some of the new trends and emerging issues, including prepandemic strategies for H5N1 avian influenza vaccines, now that some countries are stockpiling them.


Keiji Fukuda, MD, MPH, coordinator of the World Health Organization's (WHO's) global influenza program, told reporters that experts don't really know what virus will spark the next global pandemic, but given the persistent and lethal nature of the H5N1 virus, the WHO has received pledges from pharmaceutical manufacturers to develop a 150 million dose international vaccine stockpile. He said the stockpile is intended to stop or slow a pandemic if the outbreak is detected early enough.

The existence of individual-country H5N1 vaccine stockpiles and plans for a WHO global stockpile have raised complex questions about potential uses for the vaccine during the prepandemic period, Fukuda said.

Some countries are weighing what to do with the vaccines, especially since some doses are set to expire. Global health officials are considering other options, such as vaccinating people in high-risk countries such as China, Indonesia, or Vietnam or perhaps adding the antigen to seasonal flu vaccines as a priming strategy.

The United States, for example, has so far stockpiled about 26 million H5N1 vaccine doses, though some has already expired or is about to expire, according to a Sep 2008 report on US pandemic vaccine policy from the Congressional Budget Office (CBO). The HHS has launched studies to determine how long stockpiled vaccines remain safe and effective, but in the meanwhile it assumes a 2-year shelf life.

The United Kingdom has stockpiled 3 million doses of H5N1 vaccine. Several countries have announced stockpiling plans, including France, Ireland, Italy, and Austria, according to the CBO report. Other countries such as Japan are in the midst of clinical trials to produce their own H5N1 vaccines.

During a Jan 28 US Department of Health and Human Services (HHS) webcast update on the status of the nation's pandemic preparedness, Robin Robinson, director of the HHS Biomedical Advanced Research and Development Authority (BARDA), said the influenza community this year will discuss the possibility of adding H5N1 antigen to the seasonal flu vaccine. "The benefit is that it could provide some priming . . . the counter side is that we don't know yet what this H5N1 vaccine would be like in millions of people in a seasonal situation," he said.

Robinson added that health officials are highly sensitive of the 1976 experience with the swine flu immunization, when some cases of Guillian-Barre syndrome were associated with the vaccine.

Fukuda said the WHO's Strategic Advisory Group of Experts (SAGE) on immunization will meet in early April to discuss potential uses of H5N1 vaccine during the prepandemic period.

In November 2008, the WHO established a SAGE working group to focus on H5N1 vaccine issues. According to the Jan 9 issue of the WHO Weekly Epidemiological Record, the working group said it would address:
* Use of the H5N1 vaccine during the prepandemic period to protect people in high-risk jobs, such as cullers, essential workers, and the public
* Priming and immunization strategies for essential workers and the general public
* Recommendations to the WHO and other groups on what to do with H5N1 doses that are about to expire
* Possible changes to the projected size of the WHO's H5N1 vaccine stockpile

"It's likely that different countries will look at this issue differently. This is quite an important pivotal discussion," Fukuda said. Though the WHO's stockpile is still in a virtual state, made up of pledges from pharmaceutical companies, Fukuda said countries that have real stockpiles are facing imminent issues about what to do with expiring H5N1 vaccine. "This will be a country-by-country decision," he said.

Arnold Monto, MD, an influenza epidemiologist at the University of Michigan, told reporters that some experts began discussing the possibility of adding H5N1 antigen to the seasonal flu vaccine a few years ago, but he said some elements of the vaccine have changed since then.

For example, he said more companies are developing H5N1 vaccines that use adjuvants, or immune-boosting chemicals, as a dose-sparing strategy, which might complicate combining the H5N1 component with the seasonal flu vaccine. Also, he said unlike single-dose seasonal flu vaccines, the H5N1 vaccine is given in two doses.

Though Monto predicted that discussions will continue on the appropriate use of the H5N1 vaccine, he said new uses for the vaccine won't happen anytime soon.

Among other possibilities for the H5N1 vaccine, pharmaceutical companies might some day market the product to the public, Monto said, adding that if the H5N1 virus ever turns up in North American birds, Americans might demand the vaccine.

At today's press conference, influenza experts also provided updates on other influenza topics:
* The US flu season has been relatively mild, said Nancy Cox, PhD, director of the influenza division at the Centers for Disease Control and Prevention (CDC). She said she expects flu activity to increase over the coming weeks as the season peaks. "Remember, it's not too late to get the seasonal flu vaccine," she said.
* Among several suggestions to improve the seasonal flu vaccine, experts are considering adding a second influenza B strain to the vaccine to help solve the problem of deciding which strain to add, said Monto. Early returns this season suggest that Victoria strains are more common, though this season's vaccine contains the Yamagata strain.
* Much more work is needed on bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), that cause influenza complications, said Andrew Pavia, MD, chair of the IDSA National and Global Public Health Committee. Pavia also said more work is needed to develop better treatments and determine who is at increased risk of dying from the complications.
* A road map for influenza research is being fleshed out by the Wellcome Trust, an independent medical research funding charity based in London, said Frederick Hayden, MD, an influenza expert at the University of Virginia School of Medicine in Charlottesville. He said the process will help identify research gaps.
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<cite cite="http://www.cidrap.umn.edu/cidrap/content/influenza/panflu/news/feb0309antigens-jw.html">CIDRAP >> Experts weigh new H5N1 vaccine strategies</cite>