Bird Flu

Scientists rule out spreading of bird flu by migrant birds in India
NEW DELHI, April 14 (Xinhua) -- International researchers have recently ruled out the spreading of avian influenza or bird flu virus by migratory birds through a review of migratory bird movement, reported local daily Mail Today Tuesday.
All samples studies for virus strain H5N1 on migrant birds so far were found to be negative, said the report.
The researchers monitored in real time the movement of migratory birds from India in a northward direction using satellite tracking technology. They ruled out the possibility of involvement of migratory birds in avian influenza spreading in India, said the report.
The satellite monitoring gave valuable data about the movement of migratory birds in the region and has enabled scientists to determine whether the locations of these birds and outbreaks of bird flu are related along the birds' migratory pathways, according to the report.
The project began last December when scientists captured, sampled and marked 70 water birds with "satellite tags" at Chilika Lagoon in India, where over 8,900,000 migratory and resident water birds used to live as their temporary or permanent residence, said the report. Scientists at the U.S. Centers for Disease Control and Prevention (CDC) have found that just two small changes in the virus that caused the 1918 Spanish flu pandemic stopped it from jumping between mammals in the laboratory.Dr. Terrence Tumpey, who led the research says they believe their finding could help determine what will cause the next pandemic.
The researchers who have been studying a reconstructed version of the 1918 virus found it very easy to stop it from spreading from one infected ferret to another, although the altered viruses still quickly killed the animals.
Although the finding does not reveal whether or how the dreaded H5N1 bird flu virus would change to be able to pass between humans, it does illustrate that a certain type of biological change may be crucial in causing pandemics.
CDC Director Dr. Julie Gerberding says such research is vital as the more that is learned about what may have contributed to the spread and deadliness of the 1918 pandemic will mean better preparations can be made for the next pandemic.
World experts have been concerned for some time that a pandemic could happen at any time and the most likely suspect is H5N1 avian influenza currently circulating.
The H5N1 strain of the virus has to date killed over 160 people worldwide, and resulted in the deaths either by infection or by preventative culling, of millions of birds and poultry.
Influenza presents such a problem because the virus mutates regularly, is easily spread and kills people.
According to the World Health Organization seasonal flu claims the lives of between 250,000 and 500,000 people a year and every 30 years or so, along comes a strain which will make a big mutation and suddenly become more deadly.
The 1918 pandemic, caused by the H1N1 virus, was responsible for 50 million deaths worldwide over a two year period.
The current strain of H5N1 has killed more than half of its human victims.
The only positive at present is that its current form does not infect people easily and as been almost always been transmitted via infected birds or poultry.
If the scientists can establish which mutations would render H5N1 able to pass easily from person to person they might then be able to predict or even control the spread of the virus.
When the CDC team reactivated the 1918 H1N1 virus they infected caged ferrets with either the original flu virus (reconstructed two years ago) or the altered form.
The cages of the infected ferrets were later placed next to healthy animals to see if the virus would spread through the air.
Tumpey says they found that the 1918 virus spread very efficiently while the altered virus did not spread at all.
Tumpey, a senior microbiologist at the CDC, says by using genetic engineering they made a modest change of two amino acids in the hemagglutinin protein (the "H" in an influenza virus name) that stopped the transmission of the virus between the ferrets.
Therefore it is possible that the hemagglutinin, found on the surface of flu viruses, is what enables it to transmit efficiently from one person to another.
In order for an influenza virus to spread efficiently, it needs to attach itself to the cells in the human upper airway instead of to cells in the gastrointestinal tracts of birds and somehow the H1N1 bird virus adapted itself to humans.
H5N1 is a bird virus that has not as yet made this change and Tumpey suspects changes in more than one virus protein would be needed for the H5N1 virus to be transmitted among humans.
The researchers say the mutations that enabled H1N1 to move from birds to people do not make H5N1 shift in the same way.
The research is published online in the February 1 issue of Science.
Drug companies have increased their capacity to make bird flu vaccines by 300% in the past two years but will still need four years to meet global demand in the event of a pandemic, a study says.
It also said doses of vaccine tailored to the actual strain of pandemic influenza that emerges will not be available until four months after that strain is identified.
"We found that considerable progress has been made to enhance the production capacity of pandemic influenza vaccine," Adam Sabow, partner at consultanting firm Oliver Wyman which conducted the study, said in a statement.
"While capacity still falls short of global need during a pandemic, the surplus capacity during the inter-pandemic period creates opportunities for preparedness efforts," he said.
Oliver Wyman carried out the study with the World Health Organisation (WHO) and International Federation of Pharmaceutical Manufacturers and Associations (IFPMA).
Manufacturers hunting for the best vaccines to stop the deadly disease face a race against the clock if the H5N1 strain of influenza now circulating in birds mutates and starts spreading easily among humans, as many researchers fear.
In the most likely case, manufacturers could produce 2.5 billion doses of pandemic vaccine in the 12 months following receipt of the production strain, requiring four years to satisfy global demand, the study said.
AdvertisementIn the current best-case scenario, 7.7 billion doses could be produced in the first 12 months, requiring 1.5 years to satisfy global demand, it said. Production was expected to increase significantly over the next five years.
Effective coverage through mass immunisation is based on two doses per person for a global population of 6.7 billion.
GlaxoSmithKline , Europe's biggest drugmaker, and Sanofi-Aventis , whose vaccines arm is Sanofi Pasteur, and Swiss drugmaker Novartis are among at least 16 companies working on pandemic vaccines.
"The findings suggest that the early use of stockpiled H5N1-based vaccines, followed by pandemic vaccines as soon as these become available, offers a realistic strategy to address this significant threat," IFPMA Director-General Alicia Greenidge said in a statement.
Geneva-based IFPMA links 26 leading international companies and 44 national and regional industry associations. Oliver Wyman also talked to 11 other current or potential vaccine makers in developing countries who are not members of IFPMA.
The bird flu virus has killed 254 people out of 408 infected worldwide since 2003, according to the WHO, a United Nations agency which has warned that a pandemic could kill millions.
A challenge in producing a vaccine for millions of people around the world is how to make the maximum number of shots from the minimum amount of antigen, or active ingredient.