An illustration of the mechanism of action of a messenger<unk>  The goal of a vaccine is to stimulate the adaptive immune system to create antibodies that precisely target that particular pathogen. The markers on the pathogen that the antibodies target are called antigens. Traditional vaccines stimulate an antibody response by injecting either antigens, an attenuated (weakened) virus, an inactivated (dead) virus, or a recombinant antigen-encoding viral vector (harmless carrier virus with an antigen transgene) into the body. These antigens and viruses are prepared and grown outside the body. In contrast,<unk> s introduce a short-lived synthetically created fragment of the RNA sequence of a virus into the individual being vaccinated. These<unk>  fragments are taken up by dendritic cells through phagocytosis. The dendritic cells use their internal machinery (ribosomes) to read the<unk>  and produce the viral antigens that the<unk>  encodes. The body degrades the<unk>  fragments within a few days of introduction. Although non-immune cells can potentially also absorb vaccine<unk> , produce antigens, and display the antigens on their surfaces, dendritic cells absorb the<unk>  globules much more readily. The<unk>  fragments are translated in the cytoplasm and do not affect the body's genomic DNA, located separately in the cell nucleus. Once the viral antigens are produced by the host cell, the normal adaptive immune system processes are followed. Antigens are broken down by proteasomes. Class I and class II MHC molecules then attach to the antigen and transport it to the cellular membrane, "activating" the dendritic cell. Once activated, dendritic cells migrate to lymph nodes, where they present the antigen to T cells and B cells. This triggers the production of antibodies specifically targeted to the antigen, ultimately resulting in immunity.
MRNA vaccine
Viral vector vaccine
Genetic vaccine
DNA vaccine
Cell-based vaccine
Hexavalent vaccine
Conjugate vaccine
Synthetic vaccine