”2020 har varit det fjärde bästa året någonsin”

An RNA vaccine or mRNA (messenger RNA) vaccine is a type of vaccine that uses a copy of a natural chemical called messenger RNA (mRNA) to produce an immune response. The vaccine transfects molecules of synthetic RNA into immunity cells. Once inside the immune cells, the vaccine's RNA functions as mRNA, causing the cells to build the foreign protein that would normally be produced by a pathogen (such as a virus) or by a cancer cell. These protein molecules stimulate an adaptive immune response which teaches the body how to identify and destroy the corresponding pathogen or cancer cells. The delivery of mRNA is achieved by a co-formulation of the molecule into lipid nanoparticles which protect the RNA strands and helps their absorption into the cells.Reactogenicity, the property of a vaccine of being able to produce common, "expected" adverse reactions, is similar to that of conventional, non-RNA, vaccines. People susceptible to an autoimmune response may have an adverse reaction to RNA vaccines. The advantages of RNA vaccines over traditional protein vaccines are superior design and production speed, lower cost of production, and the induction of both cellular as well as humoral immunity. A disadvantage in the Pfizer-BioNTech mRNA vaccine for COVID-19 is that it requires ultracold storage before distribution. In RNA therapeutics, mRNA vaccines have attracted considerable interest as COVID-19 vaccines. By early December 2020, there were two novel mRNA vaccines for COVID-19 that had completed the required eight-week period post-final human trials and were awaiting emergency use authorization (EUA): Moderna's COVID-19 vaccine (mRNA-1273), and Pfizer-BioNTech's COVID-19 vaccine (tozinameran). On 2 December 2020, the UK's Medicines and Healthcare products Regulatory Agency (MHRA) became the first medicines regulator to approve an mRNA vaccine, authorizing Pfizer-BioNTech's COVID-19 vaccine (active ingredient tozinameran) for widespread use. On 11 December in the US the FDA gave EUA for Pfizer-BioNTech's COVID-19 vaccine. On 21 December 2020 the US Centers for Disease Control and Prevention (CDC) recommended emergency use authorization for Moderna's COVID-19 vaccine in adults. This had been approved by the FDA three days earlier.The use of RNA in a vaccine has been the basis of substantial misinformation circulated via social media, wrongly claiming that the use of RNA alters a person's DNA, or emphasizing the technology's previously unknown safety record, while ignoring the more recent accumulation of evidence from trials involving tens of thousands of people.