RNA vaccine, conceptual illustration. Close-up of molecules of RNA (ribonucleic acid, blue helix) enclosed in lipid nanoparticles that have just been injected into a patient. The RNA will be taken up and read by the body's cells, causing them to produce copies of viral proteins. The viral proteins will provoke an immune response, priming the body against infection with the actual virus. The first RNA vaccine approved for human use, developed against the SARS-CoV-2 coronavirus by Pfizer/BioNTech, was approved in the UK on 2nd December 2020.