A shark conservation group estimates that 500,000 sharks could be killed in the race to produce an effective Covid-19 vaccine for the global population. Several vaccine candidates require an ingredient sourced from shark livers, and as the pressure to produce a vaccine intensifies, sharks could be caught in the middle, reports Gavin Butler for Vice News.
Pharmaceuticals are specifically after the sharks’ oily livers, which produce a compound called squalene. It’s a sought-after ingredient in cosmetics due to its moisturizing properties, but it’s also used in vaccines as an “adjuvant,” an agent that can elicit a stronger immune response, reports Katie Camero for the Miami Herald.
As of September 29, about 17 vaccines out of the 176 candidates in preclinical and clinical evaluations use adjuvants. And of those, five vaccine adjuvents are squalene-based. One of which is MF59, which contains around 9.75 milligrams of squalene per dose.
If MF59 is used in a vaccine produced to treat everyone in the world, nearly 250,000 sharks will be killed, estimates Shark Allies, a non-profit organization advocating for shark conservation. And if two doses of the vaccine are needed—a likely scenario, according to experts—nearly half a million sharks will perish.
Stefanie Brendl, founder and executive director of Shark Allies tells Vice News in an email that people aren’t “going out to specifically kill sharks right now just to get enough for a vaccine.” But if the global population becomes dependent on squalene in future coronavirus vaccine production, it could take a huge toll on shark populations, many of which are already threatened.
“It's something we need to get ahead of ASAP, because we are facing many years of vaccine production, for a global population, for many more coronavirus vaccines to come,” Brendl tells Vice News. “The real danger is in what this can turn into in the future. A reliance on shark oil for a global vaccine—it’s truly insane. A wild animal is not a reliable source and cannot sustain ongoing commercial pressure. [And] the overfishing of sharks globally is already at critical levels.”
The squalene industry already kills around 3 million sharks each year, reports the Miami Herald. Many shark species are already in danger of extinction because they face threats from overfishing and the shark fin trade, which kill 100 million sharks globally each year.
Hammerheads, great whites, and whale sharks are among the most targeted species for their livers. But deep-sea sharks are also high-risk: Squalene helps sharks maintain buoyancy underwater, and those living in deeper waters have oilier livers. Deep sea shark species, however, are long-lived and grow slowly, which make recovery from overfishing complicated. Shark Allies worries that a dependence on the sharks’ squalene will spell disaster for species already teetering on the edge of extinction.
Brendl isn’t demanding that pharmaceuticals slow down or stop their work, but she requests that they resort to plant-based alternatives such as olive oil, sugarcane, bacteria, and yeast, which have varying levels of success as adjuvants. However, those options can be 30 percent more expensive and take much longer to extract than squalene from sharks, the Miami Herald reports.
“The industries stand to profit immensely from having a global vaccine,” Brendl tells Vice News. “It is reasonable to ask that they start thinking about a reliable and sustainable production.”