RNA vaccine, conceptual illustration. A molecule of RNA (ribonucleic acid, blue helix) is being injected at right. The RNA is taken up and read by the body's cells, causing them to produce copies of viral proteins (red). The viral proteins provoke an immune response, leading to the production of antibodies (purple) against the protein, and priming the body against infection with the actual virus. The first RNA vaccine approved for human use, developed against the SARS-CoV-2 coronavirus (round) by Pfizer/BioNTech, was approved in the UK on 2nd December 2020.