The administration of PEGylated drugs can lead to the production of anti-PEG antibodies(anti-PEG immunoglobulin M (IgM)) and immune response (Figure 1) [30]. Due to these phenomena,the PEG-conjugation of drugs/NPs often only provides a biological advantage during the first dose of a treatment course. By the second dose, the PEGylated agents have been recognized by themononuclear phagocyte system in the spleen and liver and are rapidly cleared from circulation.
Polyethylene glycol or PEG is the lipid with which the mRNA is coated and it seems the body starts attacking it with repeated treatments.
This means repeated usage of drugs that contain PEG reduces the efficiency per dose and increases side effects. However after speaking with a doctor who told me a lot about the involved gears, I don’t think this is a huge deal for giving a human two doses of an mRNA vaccine.
Antibody buildup against polyethylene glycol or PEG. One issue of concern was voiced in The Importance of Poly(ethylene glycol) Alternativesfor Overcoming PEG Immunogenicity in DrugDelivery and Bioconjugation:
Polyethylene glycol or PEG is the lipid with which the mRNA is coated and it seems the body starts attacking it with repeated treatments.
This means repeated usage of drugs that contain PEG reduces the efficiency per dose and increases side effects. However after speaking with a doctor who told me a lot about the involved gears, I don’t think this is a huge deal for giving a human two doses of an mRNA vaccine.