evidence: COVID-19 mRNA Vaccine BNT162b2 encodes a mutant viral spike (S) protein of SARS-CoV-2, with two point mutations inserted to lock S in an antigenically preferred prefusion conformation (P2 S). It is formulated as an RNA-lipid nanoparticle of nucleosidemodified mRNA containing N1-methylpseudouridine instead of uridine. Encapsulation into lipid nanoparticles enables transfection of the mRNA into host cells after intramuscular injection. During mixing of the RNA and the dissolved lipids, the lipids form the nanoparticles encapsulating the RNA. After injection, the lipid nanoparticles are taken up by the cells, and the RNA is released into the cytosol. In the cytosol, the RNA is translated into the encoded viral protein. The viral spike (S) protein antigen induces an adaptive immune response through neutralising antibodies. Furthermore, as the expressed spike (S) protein is being degraded intracellularly, the resulting peptides can be presented at the cell surface, triggering a specific T cell-mediated immune response with activity against the virus and infected cells. [...] The active substance of COVID-19 mRNA Vaccine BNT162b2 is N1-methylpseudouridine instead of uridine containing mRNA expressing full-length SARS-CoV-2 spike protein with two proline mutations (P2 S) to lock the transmembrane protein in an antigenically optimal prefusion conformation. The vaccine is formulated in lipid nanoparticles (LNPs). The LNP is composed of 4 lipids: ALC-0315, ALC-0159, 1,2-distearoyl-sn-glycero-3-phosphocoline (DSPC), and cholesterol. Of the four lipids used as excipients in the LNP formulation, two are naturally occurring (cholesterol and DSPC) and will be metabolised and excreted like their endogenous counterparts.