RNA-Vaccines

RNA vaccines are vaccines which, in contrast to classical live vaccines, do not contain attenuated pathogens, but only the pathogen gene in question in the form of single-stranded messenger ribonucleic acid (mRNA). RNA vaccines are relatively easy to synthesize, as this can be done "in the lab" without the need for vital bacteria or cells.

RNA vaccines such as BNT162 (BioNTech/Fosun/Pfizer) and mRNA-1273 (Moderna/NIAID) usually consist of single-stranded messenger ribonucleic acid (mRNA). In the cytosol of the cell, the mRNA is bound by ribosomes. The mRNA contains the genetic information for building a protein. In the case of COVID-19, the BNT162 vaccine generates the spike protein of the virus.

To facilitate uptake into the cytosol, the vaccine RNA can be packaged in liposomes or lipid nanoparticles (LNP), for example.

Furthermore, self-replicating or self-amplifying synthetic RNA(saRNA) such as BNT162 is also used. These code both for the corresponding viral antigen (spike protein) and for proteins that enable the replication of RNA vaccines so that the vaccination dose can be reduced. SaRNA vaccines are derived from alphaviruses (positive-stranded RNA viruses without segmentation).

RNA-based vaccines are generally considered to be very safe. Since the mRNA manufacturing process does not require toxic chemicals or cell cultures that could be contaminated with viruses. Also, the short manufacturing time for mRNA offers few opportunities to introduce contaminating microorganisms.