Amid references to monkeys, moths and other complicated jargon, we break down the ingredient lists for each Covid-19 vaccine approved for use in the UK.
So far the national medicines regulator has given the green light to four types of jab, with others currently pending.
Pharmaceutical companies have been approaching the vaccine from a number of angles – which each require a different method of production.
The Oxford-AstraZeneca and Janssen (the pharmaceutical wing of Johnson & Johnson) use a genetically modified virus, while the Pfizer-BioNTech and Moderna jabs use part of the coronavirus’s genetic code.
While each works in a similar way, they all use different methods to get there.
With help from top professor Jun Wei, we look at the different types of Covid vaccine on offer – and what each contains.
How do the jabs work?
What’s in my Covid vaccine?
Concerns have also been raised around the ingredients contained within each Covid vaccine.
At first glance, the inclusion of hydrochloric acid, pure alcohol and even table salt could seem alarming.
But many of these ingredients are commonplace in everyday items including food and cosmetics, while others have gone through extensive testing to ensure they are safe.
Some, including ethanol (alcohol), are even produced naturally by our bodies on a daily basis.
Here are the ingredient lists for the four Covid vaccines currently approved for use in the UK, as seen on their patient information leaflets, and what they mean: