Stories tagged H5N1

Jan
18
2009

Bird flu rears its head again in China

Bird flu death in China
Bird flu death in ChinaCourtesy broterham
A two year old girl in northern China has tested positive for bird flu. Early this month, January 5, a 19-year-old Beijing woman died of bird flu after handling poultry. She had purchased ducks at a market in Hebei Province, which neighbors Beijing. Although she had close contact with 116 people, no one around her has fallen ill.

Pandemic possibilities worry officials

Human-to-human transmission of avian flu is rare, but officials worry the virus could mutate and become a deadly pandemic. H5N1 has led to 248 deaths worldwide since 2003, including 21 in China.

Source articles:
Click this link to read all CNN articles about bird flu

May
29
2007

Blood from bird flu survivors successfully treats H5N1 virus in mice.

Treatment for H5N1
Treatment for H5N1
The antibodies worked well when administered three days after the mice were infected, with all 20 mice in the treatment groups surviving, compared with none out of five in the control group. Antibody-producing white blood cells, called memory B cells, were separated from the blood of four Vietnamese who had recovered from H5N1 influenza (bird flu). In Switzerland, Dr. Lanzavecchia treated them with a process he developed so that they rapidly and continuously produced large amounts of antibody.

Next, researchers in Dr. Subbarao's lab screened 11,000 antibody-containing samples provided by the Swiss team and found a handful able to neutralize H5N1 influenza virus. Based on these results, Dr. Lanzavecchia purified the B cells and ultimately created four monoclonal antibodies (mAbs) that secrete H5N1-specific neutralizing antibodies." Science Daily

Human antibodies used in flu pandemic of 1918.

Using blood products from influenza survivors is an old idea, the researchers note. During the flu pandemic of 1918-19, for example, physicians took serum from recovered flu patients and gave it to new victims. A recent study suggests it halved the death rate, from 37% to 16%.

Antibodies are costlier and harder to mass produce.

The new antibody treatment could be used together with antivirals:

“What we are trying to do is add another arrow to the quiver of options for treating patients with H5N1 infection," says Cameron Simmons, who led the study. New Scientist

Because the survival rate was excellent even when treatment was delayed for three days, this antibody treatment would work well in treating the few people who catch the disease directly from birds, and for localized outbreaks. For large scale prevention against bird flu, antiviral drugs such as Tamiflu are the still the best defense.

Research article in PLoS Medicine: Prophylactic and Therapeutic Efficacy of Human Monoclonal Antibodies against H5N1 Influenza.

Mar
19
2007

Indonesia—with the world's highest death toll from H5N1 avian influenza—briefly stopped providing samples to the World Health Organization (WHO), saying only organizations that agreed not to use the samples for commercial purposes would have access. Now the Indonesian government has struck a new deal to share samples under a plan that would guarantee access to any resulting vaccines.

H5N1 avian influenza viruses: This is a colorized transmission electron micrograph of Avian influenza A H5N1 viruses (in gold). (Courtesy J. Katz Goldsmith and S. Zaki, CDC)
H5N1 avian influenza viruses: This is a colorized transmission electron micrograph of Avian influenza A H5N1 viruses (in gold). (Courtesy J. Katz Goldsmith and S. Zaki, CDC)

The Reuters article says,

"Indonesia has said it was unfair for foreign drug firms to use samples, design vaccines, patent them and sell the product back to the country. ...

Menno de Jong of the Oxford University Clinical Research Unit in Vietnam's Ho Chi Minh City said sharing viruses and clinical data was vital to improve diagnostics, clinical care and vaccine development, but sharing vaccines was vital too.

'I think the point is well taken from the Indonesia experience that there should be some guarantees for countries affected by H5N1 that they will also share in the vaccines produced,' he said."

Biotech and pharmaceutical companies spend BIG money to produce tests, treatments, and vaccines for a huge range of conditions, from the life-threatening to the merely inconvenient or uncomfortable. And they’re understandably concerned about protecting their investments.

But afflicted patients are usually not compensated for the samples that make these medical miracles possible. (For a good discussion of the problem, read this editorial from the New York Times).

Check out Bryan’s blog entry ((“Patenting human genes”), and then vote in our poll.

Tell us what you think: Does Indonesia’s insistence that compensation (in the form of access to resulting vaccines) for H5N1 avian influenza samples make you feel safer/better?

The study will enroll 45 volunteers between the ages of 18 and 60. Fifteen will receive placebo injections and 30 will receive three injections of the investigational vaccine over 2 months and will be followed for 1 year. Volunteers will not be exposed to influenza virus. ScienceDaily

Jul
18
2006

A new type of vaccine: New H5N1 vaccine trial. photo credit; WikiMedia,
A new type of vaccine: New H5N1 vaccine trial. photo credit; WikiMedia,

Are we ready for an avian flu pandemic?

Current flu vaccines require live chicken eggs and six months of brewing time. This method may provide too little, too late. A new, quicker, type of vaccine production and delivery system has been approved for trial in August. A company called PowderMed has produced vaccine by cloning a gene from the current circulating bird flu strain and slotting it into an existing DNA backbone vaccine. This "plug and play" system would enable rapid adaptation of the vaccine to include relevant DNA if a new and more dangerous strain develops. It is then enclosed in tiny gold particles and delivered using an injector powered by concentrated helium gas, which pushes the particles into the skin.

“We are very excited by the potential for our flu vaccine technology to address the major healthcare challenge that influenza presents, in particular in the event of an avian flu or other pandemic outbreak. Our technology has significant advantages over current flu vaccine technology particularly in terms of the speed of response in the event of a pandemic. As soon as a new influenza strain becomes known, our “plug and play” system would enable us to rapidly insert the relevant DNA gene cassette into our standard DNA backbone. A PowderMed manufacturing facility will be capable of delivering the vaccine requirements of an entire country within 3 months. This is not possible for other technologies.”
Just 1.2kg of vaccine DNA would be sufficient to vaccinate the entire population of the US twice - an initial dose and a booster dose. PowderMed has carried out a detailed feasibility study with contract manufacturing partners, which concludes that it could establish a manufacturing capability with a surge capacity of 150 million influenza vaccine doses in a three-month period. Dr Dix points out that this is critical since, “No other vaccine technology offers this speed of response. In the event of a pandemic, most deaths and illness will occur in the first six months of an outbreak. We believe that our technology offers the best potential to save lives and minimise the economic impact of a flu pandemic.” Dr Clive Dix, CEO of PowderMed

Sources:
Reuters
PowderMed press release(pdf)

Oct
10
2005

It's in the news. People are dying from a relative of the 1918 Influenza virus half a world away, and scientists fear it may be the next pandemic. Sounds like science fiction, or the latest box-office smash, right? Unfortunately, it's real, and is happening right now.

chickens: (Photo courtesy Laura Hadden)
chickens: (Photo courtesy Laura Hadden)

In Southeast Asia, a virus known as avian influenza or avian flu has the potential to spread and kill humans with terrifying speed. Avian flu is also known as H5N1 for the proteins that bind, infect, and destroy its host cell to thrive. Chickens can die within hours of exposure, swollen and hemorrhaging, but it is just as lethal to mammals from lab mice to tigers. The virus has decimated bird flocks in 11 countries mostly in Asia, and has killed 62 people (half the known cases) to date, with highest fatalities occurring in Vietnam, Cambodia, and Thailand. So far, nearly all people infected contracted the sickness directly from infected poultry and at this point there is no confirmed evidence of efficient human-to-human transmission. However, health authorities fear that the H5N1 strain will likely mutate into a pathogen easily passed between humans if it continues to persist in the environment. If that happens, and authorities believe it's only a matter of time, the world could face a catastrophic pandemic.

Many health organizations and governments are stockpiling a drug (Tamiflu) to protect against this potential pandemic, but scientists are reporting that a strain of H5N1 avian flu virus is showing resistance to the antiviral drug. Scientists are working to avoid this disaster by detecting changes in the evolving H5N1 virus. As a first step, scientists have rebuilt the 1918 flu-a disease that killed as many as 50 million people-from pieces of genetic material retrieved from the lungs of people who died 87 years ago. Gene-swapping experiments are starting to give scientists some clues in the lab. When small substitutions were made, the reconstructed virus could no longer replicate in the lungs of mice, kill animals, or attach itself to human lung cells.

So far H5N1 has not yet learned the trick of racing from person to person like the ordinary flu and maybe never will. Nevertheless, experts fear that the risk could materialize and are urging the world to prepare for the worst.

United Nations Food and Agriculture Program

NPR Health and Science Report