upright=1 An<unk>  is a type of vaccine that uses a copy of a molecule called messenger RNA <unk>  to produce an immune response. The vaccine delivers molecules of antigen-encoding<unk>  into immune cells, which use the designed<unk>  as a blueprint to build 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 that teaches the body to identify and destroy the corresponding pathogen or cancer cells. The<unk>  is delivered by a co-formulation of the RNA encapsulated in lipid nanoparticles that protect the RNA strands and help their absorption into the cells. thumbtime=156 Reactogenicity, the tendency of a vaccine to produce adverse reactions, is similar to that of conventional non-RNA vaccines. People susceptible to an autoimmune response may have an adverse reaction to messenger<unk> s. The advantages of<unk> s over traditional vaccines are ease of design, speed and lower cost of production, the induction of both cellular and humoral immunity, and lack of interaction with the genomic DNA. While some messenger<unk> s, such as the Pfizer–BioNTech COVID-19 vaccine, have the disadvantage of requiring ultracold storage before distribution, other<unk> s, such as the Moderna, CureVac, and Walvax COVID-19 vaccines, do not have such requirements. In RNA therapeutics, messenger<unk> s have attracted considerable interest as COVID-19 vaccines. In December 2020, Pfizer–BioNTech and Moderna obtained authorization for their<unk> -based COVID-19 vaccines. On 2 December, the UK Medicines and Healthcare products Regulatory Agency (MHRA) became the first medicines regulator to approve an<unk> , authorizing the Pfizer–BioNTech vaccine for widespread use. On 11 December, the US Food and Drug Administration (FDA) issued an emergency use authorization for the Pfizer–BioNTech vaccine and a week later similarly authorized the Moderna vaccine.
MRNA vaccine
Viral vector vaccine
Genetic vaccine
DNA vaccine
Cell-based vaccine
Hexavalent vaccine
Conjugate vaccine
Synthetic vaccine