What is Squalene and Why is it Important?
Squalene is a natural organic compound obtained from shark liver oil and vegetable oils including amaranth seed, rice bran, wheat germ, and olives. Squalene is commonly used in cosmetics and skin care products, and in some adjuvants which are a component of certain vaccines. Adjuvants are intended to increase a human body’s immune response to a vaccine, thereby increasing its efficacy. The inclusion of adjuvants in vaccines allows for less of the active vaccine ingredients/antigen (i.e. dead or weakened viruses or bacteria) to be contained in a single dose. As a result, more vaccines can be produced. For many years, squalene-adjuvanted vaccines have been used to treat or prevent diseases including strains of influenza and coronaviruses (H1N1, H5N1, H7N9, H7N7, SARS-CoV, and MERS-CoV, influenza, and rabies), and several of the adjuvants used in COVID-19 vaccines currently being tested use shark squalene while the squalene source for others are uncomfirmed. However, Amyris reports they have developed a process using sugarcane as a sustainable alternative to shark squalene adjuvant.
So why do companies use shark-derived squalene in their adjuvants instead of sustainable plant-based alternatives? Plant-derived squalene may require up to 70 hours to process. By contrast, processing squalene from the livers of these sharks takes just 10 hours, however, around 3,000 sharks are killed to extract 1000 kg (2204.62 lbs) of squalene which makes true cost of catching the sharks and transporting them to processing plants very high. Sharks play an important role in maintaining a healthy ocean ecosystem but about half of the shark species targeted for their livers are listed as “Vulnerable” to extinction by the IUCN Red List, thus the significant damage to the marine ecosystem caused by their removal questions the justification for use of shark-derived squalene.
No one is asking any company to slow down the process of testing or the eventual manufacturing of a COVID-19 vaccine. Instead, shark and ocean conservationists are asking these companies to replace the shark squalene in vaccine adjuvants with plant-based alternatives.