Recent studies point to polyethylene glycol lipid, which is used as an additive in mRNA-LNP vaccines, as the cause of the anaphylactic reaction55,56. PEGylation is the introduction of PEG into a drug, which amplifies vaccine stability to enhance plasma half-life and reduces immunogenicity to improve clinical efficacy. PEGylation lowers the clearance rate by the mononuclear phagocytic cells of the liver and spleen and interferes with the binding of the protein opsonin to liposomes57,58,59,60
Polyethylene glycol is PEG