Since the beginning of the pandemic, there has been non-stop talk of a vaccine for SARS CoV-2 which will put this whole coronavirus episode behind us and allow us to move forwards. At the time of writing, there are hopes that a potential vaccine will be available from December of this year. In the USA, Pfizer have stated that they are likely to submit their Covid-19 vaccine to the FDA in November 2020.
However, on the flip side, we have also been inundated with news that the coral reefs are dying due to warm sea temperatures due to global warming and that up to one million animal species are now threatened with extinction due to human activity.
We know that the coronavirus pandemic spilled over from animals as has all other outbreaks in the past 20 years such as SARS, MERS, swine flu and avian flu. This shows that human activity has increasingly encroached on wildlife populations and this causes them to enter our environment and facilitates the spread of pathogens between wild animals and humans.
Most recently, there is also the discovery that the use of squalene, an adjuvant used in vaccine manufacture might possibly be a threat to shark species all over the world, especially due to the massive and immediate need for global human vaccination against Covid-19.
What is squalene?
It is a natural product that is found in human sebum but is also found in all organisms as it is a biochemical precursor to natural steroid synthesis. It is found in high concentrations in shark liver.
Why shark liver?
Sharks don’t have swim bladders like other fish do so they need to reduce their body density with fats and oils. They do this by storing squalene in high quantities in their livers, as it is of lower density than water.
What do we use squalene for?
It has been and is still used in certain cosmetics and moisturisers.
It is also used as an emulsion to enhance and stabilise vaccine and drug delivery and it is also purported to have antioxidant and anticancer properties.
[Fox CB. Squalene emulsions for parenteral vaccine and drug delivery. Molecules 2009;14(9):3286-3312.]
[Kim S-K, Karadeniz F. Biological importance and applications of squalene and squalene. Adv Food Nutr Res 2012;65:223-33.]
Is it not found anywhere else?
It is also found in olive oil, olive leaves, wheat germ oil, rice bran oil, carrots, alfalfa, elderberry and lettuce and can be successfully extracted from some of these sources, namely olive oil processing waste. This latter source has been utilised by some cosmetic companies.
I think the main issue is that natural squalene (from sharks) is relatively inexpensive to procure and plant alternatives or synthetic variants take longer to produce, are more expensive and have not been tested for use in vaccines.
Are all Covid vaccines going to contain squalene?
Squalene is already used in the flu vaccine, something I did not know.
According to the recent article by the New York Times, a group called Shark Allies are scrutinising two companies, namely GlaxoSmithKline (GSK) and Seqirus, which manufacture adjuvants that contain about 10 milligrams of squalene per dose.
According to the article, GSK and Sequirus say that the sharks they do get the squalene from were caught for other purposes. They go on to say that GSK are committed to exploring an alternative source but have said that a squalene alternative would not be available within the time frame of the Covid -19 pandemic.
So what can be done? We need a vaccine!
Yes, I don’t think anyone is asking for vaccine production to stop. We all know that many lives and whole economies are at stake. Shark Allies is asking for alternatives to shark squalene to be tested together with creating more sustainable fishing alternatives.
There are also alternatives to squalene, such as aluminium hydroxide, saponins and other surfactants which are currently being tested in vaccine manufacture as well.
[Gupta T & Gupta SK. Potential adjuvants for the development of a SARS-CoV-2 vaccine based on experimental results from other coronaviruses. Int Immunopharmacol. 2020;86:106717.]
Dr Sandy Flann, Consultant Dermatologist.
Dr Sandy Flann, Consultant Dermatologist.