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A gulper shark brought up from the ocean depths off Bermuda lies out of water in an undated photo.

A gulper shark brought up from the ocean depths off Bermuda lies out of water in an undated photo.

Photograph by Emory Kristof, National Geographic Stock

James Owen

for National Geographic News

December 29, 2009

Vaccines being made to protect people from swine flu may not be so healthy for threatened species of sharks.

That's because millions of doses of the pandemic H1N1/09 vaccine contain a substance called squalene, which is extracted from shark livers. (Get more swine flu facts.)

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 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. (Related: "Tomato, Tobacco Plants Produce SARS Vaccine.")

"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."

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.

Shark Oil Demand

Although vaccines containing squalene have not yet been approved for use in the U.S., they are being distributed elsewhere, including Europe and Canada.

Novartis, a drug company that produces swine flu vaccines containing shark squalene, did not answer requests for information about its squalene supply.

GlaxoSmithKline (GSK), another major swine-flu vaccine producer, announced in October that it had received orders for 440 million doses of vaccine containing adjuvant.

And 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.

GSK wouldn't reveal the name of its supplier or the annual quantity of shark squalene it buys. But Eldred told National Geographic News that the drug company takes about 10 percent of its supplier's total output.

O'Malley, of the Shark Safe Network, estimates 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.

This estimate, however, assumes zero waste and no refining of the squalene once it's been extracted from the sharks, O'Malley said.

Slow-Growing Sharks

Found at depths of between 984 and 4,921 feet (300 and 1,500 meters), the deep-sea sharks that produce squalene are most frequently caught via bottom trawling, either deliberately or as bycatch.

(Related: "Eight Million Sharks Killed Accidentally off Africa Yearly.")

"Bottom trawling is a horribly destructive fishing method that just bulldozes everything in its path and destroys enormous areas of the ocean floor," O'Malley said.

What's more, the already at-risk sharks are extremely slow growing and reproduce rarely.

A female gulper shark, for example, takes between 12 and 15 years to reach sexual maturity. A pregnant female gives birth to a single pup after a gestation period of about two years.

This means that the loss of a single female has a big impact on the population, said Hans Lassen, fisheries advisor for the International Council for the Exploration of the Sea, an intergovernmental organization.

In 2006 the European Union imposed deep-sea shark fishing limits in the Northeast Atlantic, and the amount of shark squalene available on the market has since been reduced.

Still, some squalene suppliers are actively soliciting fishers for these sharks, the Shark Safe Network's O'Malley said.

For instance, France-based suppler Sophim lists the species it seeks on its Web site, along with an offer to evaluate samples from shark livers that "are thrown away because fishermen don't know that the liver has a value."

Shark Liver Alternatives

Some cosmetics firms have stopped using shark squalene or are phasing it out following pressure from conservation groups.

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, she said, "we are unable to find an alternative of high enough grade."

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1 comments
Mindano Iha
Mindano Iha

Squalene is used as an adjuvant to boost the immune response of vaccines. (Immune response is not the same as immunity). You can eat it but when it’s injected, it’s seen as an invader by the immune system, antibodies against it are created, they then search for it and find it everywhere in connective tissues. By injecting squalene the risk of autoimmune reactions is increased.
Squalene is used to induce autoimmune conditions in lab animals.
The H1N1 swine flu vaccine which was used in Europe and Scandinavia contained more squalene than other vaccines on the market. This may be a reason for the increase in cases of the autoimmune condition narcolepsy.

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