Squalene, a substance extracted from shark livers is used in swine flu vaccines. Sqalene is said to be used in making a compound named adjuvant, which stimulates the human body's immune response. Though olive oil, wheat germ oil and rice bran oil also contain squalene but WHO has recommended adjuvant-based vaccines so that the drug makers use less of the active component thus increasing the available supplies. Squalene which is mainly stored in shark’s liver is lighter than water and also used in cosmetics as a natural moisturizer and personal care products.
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 – According to a report in National Geographic News.
Co-founder of the volunteer-run advocacy group Shark Safe Network, Mary O'Malley says that there are issues with using shark-liver-oil squalene since these deepwater sharks are near to extinction and have a very low reproductive rate.
O'Malley 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 : A report in National Geographic News