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Conservation groups say half a million sharks could die in the race for a cure. Photo: David Clode/Unsplash

The Inertia

Upwards of half a million sharks are facing death because of the race to create a Coronavirus vaccine, and at least one conservation group is calling for change.

Why, you ask, would a coronavirus vaccine be a threat to sharks? Well, inside the liver of sharks is an oily substance called squalene that’s used mainly in cosmetics. It’s also used, however, in a handful of adjuvants in some vaccines. Adjuvants, which, if all goes well, increase a person’s immune response to a vaccine, have been used for nearly a century. There are different kinds of adjuvants, but the ones that use squalene include a whole host of coronaviruses — like SARS-CoV, and MERS-CoV — so it makes sense that squalene would be used in a COVID-19 vaccine. But hoo boy, would that ever be bad for sharks. Now, to be clear, no one is calling for anyone to stop working towards a vaccine or even to stop using a squalene adjuvant. They’re asking that vaccine manufacturers get their squalene from somewhere other than inside a shark’s liver.

One pharmaceutical company called GlaxoSmithKline that already uses shark squalene in its adjuvant announced back in May that, should they be able to create a vaccine, they’d make a billion doses of it, which would be a “disaster for sharks and humans”, according to the campaign group Shark Allies.

Conservationists estimate that it would require about 250,000 sharks to get enough squalene to make enough doses of vaccine to immunize the world’s population with one shot. Since it would likely take two doses… well, it’s simple math. Shark Allies says that most squalene comes from places with little-to-no regulations on fisheries and fish oil production. So why would a vaccine company choose shark-squalene over, say, plant-based squalene?


“The only answer we can see is cost,” says Shark Allies. “Plant-based squalene is approximately 30 percent more expensive than shark squalene. There is very little transparency of what animals end up in squalene production. Squalene made from shark liver oil is used most commonly because it is cheap to obtain and easy to come by, not because it is more effective than other sources.”

It also takes nearly seven times longer to get squalene from a plant than it does to pull it from the liver of a shark.  “Squalene with a purity of >98 percent is obtained directly from the liver oil of a shark after a single distillation phase in a vacuum at temperatures of 200-230 degrees Celsius,” explains the conservation group. “This process takes only 10 hours whereas nearly 70 hours of processing are required to obtain olive oil squalene with a purity higher than 92 percent. The purity of non-shark-derived squalene, however, can be comparable to that of shark squalene.”

Since most shark species population levels are already dipping into the critically endangered zone, a massive increase in demand for a bit of magic hidden in their livers has a good chance of being disastrous for them.  “Harvesting something from a wild animal is never going to be sustainable,” says Stefanie Brendl, who runs Shark Allies, “especially if it’s a top predator that doesn’t reproduce in huge numbers.”


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