Scientists had been researching how to use RNA for medical purposes for more than 40 years when the COVID-19 pandemic hit in 2020.

They’d already had some success with an RNA therapeutic approved in 2018 to treat people with the rare hereditary disease familial amyloid polyneuropathy.

But the use of RNA in Pfizer-BioNTech and Moderna’s widely-used COVID vaccines put the molecule on a much bigger stage.

RNA stands for ribonucleic acid. Think of it as the spin-off of the more well-known DNA or deoxyribonucleic acid.

All humans have naturally-occurring RNA in their cells — the molecule is vital to the everyday upkeep of healthy cells and acts as the cell’s internal messaging system.

RNA is a set of instructions given by DNA, which is like the boss in the cell’s headquarters — the nucleus. These RNA instructions are sent out to the factory floor of the cell — the cytoplasm — for the cellular machinery to follow.

The field of RNA-based therapeutics lets scientists write their own set of instructions for cells to follow.

The different types of RNA allows for different types of therapeutics to be developed.

Arguably, the type of RNA that people are most familiar with is messenger RNA, abbreviated to mRNA.

mRNA is a type of coding RNA. Think of it like an instruction manual that teaches a cell to build a specific protein, similar to what you would get to build flat-pack furniture like a desk or a bookcase.

mRNA therapeutics include the COVID vaccines from Moderna and Pfizer-BioNTech, which give cells a blueprint to make their own copy of the SARS-CoV-2 spike protein in order to train people’s immune systems to recognise and defend against the virus.