Are Sharks Being Killed for Vaccines?

#EcoAdvice from our expert

Dear Dr. Donley,

I’ve read some articles recently saying that sharks are being killed to produce coronavirus vaccines. Is this true, and if it is, is there anything I can do about it?


Tell Me Some-fin good

Dear Chew-sy Vaxxer,

Aww jeez. Aren’t there any other shark-related questions you want to ask? Like, “Is shark week still a thing? And, if so, does that mean there are still people who have cable TV?” Or maybe, “Why does that Baby Shark song keep popping up on my toddler’s Pandora station even though I’ve thumbs-downed it, like, 50 times?” But no, I get to break my own record for the amount of hate mail I’ll get with the “Are vaccines killing sharks?” question.

Above all else I want to say: Please get vaccinated. I know there are a lot of anxieties around vaccines, and on the internet there are a million and one places to get information — some of it good, most of it bad. Just know that masks and a vaccine are the only way we’re going to get out the other side of this pandemic.

It didn’t have to be this way, but it is now. Vaccines are effective, and they can prevent so much suffering — but only if enough people get vaccinated. So when a vaccine is developed and our country’s top health experts — not politicians or drug companies — say it’s safe and effective, please do your part and get vaccinated.

But just because you should get vaccinated doesn’t mean vaccines are perfect. They’re not. Like many lifesaving medical advances, with vaccines sustainability is often an afterthought. It’s important to talk about these potential sustainability issues, not as a way to question vaccines’ usefulness but as a way of pushing a good thing to be even better.

Photo by David Clode on Unsplash

So: What on Earth do sharks have to do with vaccines? Well, some vaccines contain squalene, which is a naturally occurring oil in many plants and animals (including humans). Squalene, mixed with other components, is one of many “adjuvants” that can elicit an immune response and, therefore, increase the effectiveness of a vaccine.

Shark livers happen to harbor the greatest concentration of squalene on Earth. And the deeper in the depths the shark dwells, the more it’s got. Although it’s possible to extract squalene from rice, wheat, olives and other, more sustainable sources, it’s more cost-effective to extract it from a shark’s liver.

In fact, if there were a way to decrease costs by creating a weather system that could pick up the world’s sharks in some sort of wind funnel and drop them off in a processing plant, human greed would have found a way. Thankfully, that’s one less crappy horror film we all get to live through in 2020.

It’s estimated that 99% of shark-based squalene is used in cosmetics and supplements and less than 1% is being used for other purposes, like vaccines. And the 3 million or so sharks that are killed for their liver oil each year is just a fraction of the more than 100 million sharks that are killed annually, mostly through finning and bycatch from illegal fishing. So of all the sharks killed unnecessarily each year, the demand for vaccines is responsible for less than one thousandth of 1%.

To be clear, that number should be zero. That seemingly insignificant fraction equates to thousands of sharks that are being killed to put an oil in vaccines that we can easily extract from plants. And the number could also change very quickly. It’s estimated that if a squalene-based COVID-19 vaccine were adopted throughout the world, and everyone received two doses, then half a million sharks could die as a result. This is unlikely, as only five of the more than 170 COVID-19 vaccines in clinical or preclinical trials contain squalene. But it’s a worst-case possibility that should be avoided.

Exploitation of the natural world created this pandemic. It should not be a part of the fix. Vaccine manufacturers can, and should, begin to move toward squalene-free formulas or commit to sourcing 100% of their squalene from plants.

But let’s not fool ourselves that this would really “fix” the problem of sharks being cruelly killed by humans. After all, there would still be the other 99.999% of sharks being killed needlessly right now that need our help. And there are ways you can do that.

Please make sure that all your cosmetics and nutritional supplements are 100% plant-based or contain no shark-derived squalene. If you can’t confirm this from the product’s label or the manufacturer’s website, don’t buy it.

And while shark finning is illegal in U.S. waters, the trade and sale of shark fins is not. Which makes the United States complicit in this horrific practice. But fear not, the Shark Fin Sales Elimination Act almost made it into law this year — not an easy feat these days. This bill, which would make the trade of fins illegal, has broad bipartisan support and actually has a chance of being signed into law next year, once the election circus is over. Once the bill is reintroduced, please help it pass by urging your elected officials to support it.

Stay wild,

Dr. Donley

P.S. You can learn more about what the Center for Biological Diversity is doing to prevent shark finning in other countries here.

Dr. Nathan Donley is a scientist at the Center for Biological Diversity who answers questions about how environmental toxins affect people, wildlife and the environment. Send him your questions at

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Nathan Donley

Nathan Donley

Senior scientist at the Center for Biological Diversity, former cancer researcher at Oregon Health and Sciences University