H1N1 Unexpected Weakness Revealed
ANI
 Friday, December 11, 2009

Washington : A new American study has found a weakness in H1N1's method for dodging detection by the immune system.
   
Jianpeng Ma, professor in bioengineering at Rice University and graduate student Jun Shen and Qinghua Wang, an assistant professor of biochemistry and molecular biology at Baylor College of Medicine, compared the sequences of over 300 strains of H1N1 to track its evolution. The researchers were particularly examining hemagglutinin (HA), the protein "hook" that enables the virus to attach itself to and infect host cells.

Earlier research had found that five regions of H1N1's HA serve as antigenic sites, the protein fragments that activate the body's immune system. These antigenic sites constantly reorder their amino-acid sequences in the continuous cat-and-mouse game that viruses play to live on. Researchers discovered several vital residues involved in both antigenic sites and the receptor-binding site, the part of the protein that affixes to a cell and allows the virus to attack.

Ma said; "The site is known, but no one thought it was involved in the immune system. In order to recognize the receptor, that particular region has to be robust.... But it turns out this region is not only variable, but also interacts with the immune system."

If a virus eludes antibodies, all five antigenic sites would have to mask themselves by mutating. The new discovery led the researchers to believe the receptor-binding residues would also have to mutate, but not so much that the binding no longer functions.

Ma explained; "If the binding is abolished, the virus dies." He pointed out that such dual-function residues are a likely block for the virus.
He said: "It becomes a weak link and provides us with a window into the virus that we can monitor.... The virus's bottleneck is our opportunity."

Wang said: "An underlying implication is that this may not be restricted to H1N1...It may apply to other influenza viruses as well. If studying viral evolution can help predict what will cause a severe problem in humans, you can actually pre-stock vaccines, which will save time."



Source - http://www.dnaindia.com/health/report_h1n1-unexpected-weakness-revealed_1322645

Sairam,
rOhit beHaL

Swine Flu Vaccine made by Killing Sharks
ANI - Wednesday, December 30, 2009
 
Washignton: Reports indicate that vaccines being made to protect people from swine flu are developed by killing sharks, thus endangering the animals further. According to a report in National Geographic News, millions of doses of the pandemic H1N1/09 vaccine contain a substance called squalene, which is extracted from shark livers.

More commonly found in beauty products such as skin creams, squalene can be used to make an adjuvant, a compound that boosts the body's immune response. The World Health Organization (WHO) recommends adjuvant-based vaccines, because they allow drug makers to create doses that use less of the active component, increasing available supplies.

Olive oil, wheat germ oil, and rice bran oil also naturally contain squalene, albeit in smaller amounts. But for now, squalene is primarily harvested from sharks caught by commercial fishers, especially deepwater species. "There are several very disturbing issues associated with use of shark-liver-oil squalene," said Mary O'Malley, co-founder of the volunteer-run advocacy group Shark Safe Network. "The deepwater sharks targeted have extremely low reproductive rates, and many are threatened species," she added.

For example, one supplier has dubbed the gulper shark the Rolls-Royce of squalene-producing sharks, but the gulper is listed as vulnerable on the International Union for Conservation of Nature's (IUCN's) Red List of Threatened Species, meaning the species faces a high risk of extinction.

Although vaccines containing squalene have not yet been approved for use in the US', they are being distributed elsewhere, including Europe and Canada. GlaxoSmithKline (GSK), a major swine-flu vaccine producer, announced in October this year that it had received orders for 440 million doses of vaccine containing adjuvant. The adjuvant in GSK's vaccines, which have been administered in 26 countries so far, contains shark-liver squalene, company spokesperson Clare Eldred confirmed in a statement.

O'Malley, of the Shark Safe Network, estimated that GSK's 440 million doses would require at least 9,700 pounds (4,400 kilograms) of shark oil, based on the stated squalene content of 10.69 milligrams in a dose. A shark-squalene alternative isn't yet an option for adjuvant vaccine makers, according to GSK's Eldred. The drug company is currently looking at non-animal squalene sources, including olive oil. But at the moment, "we are unable to find an alternative of high enough grade," she said.


Source - http://www.dnaindia.com/health/report_swine-flu-vaccine-made-by-killing-sharks_1329112


Sairam,
rOhit beHaL