posted on 2023-03-23, 16:34authored byRasmus Münter, Erik Sørensen, Rasmus B. Hasselbalch, Esben Christensen, Susanne D. Nielsen, Peter Garred, Sisse R. Ostrowski, Henning Bundgaard, Kasper K. Iversen, Thomas L. Andresen, Jannik B. Larsen
Despite the success of mRNA-based
vaccines against infectious diseases
(including COVID-19), safety concerns have been raised relating to
the lipid nanoparticles (LNPs) used to deliver the mRNA cargo. Antibodies
against the polyethylene glycol (PEG) coating on these non-viral vectors
are present in the general population and can in some instances induce
allergic reactions. Furthermore, treatment with PEGylated therapeutics
may increase the plasma concentration of such anti-PEG antibodies.
The widespread use of PEGylated nanoparticles for mRNA vaccines concerns
researchers and clinicians about a potential rise in future cases
of allergic reactions against mRNA vaccines and cross-reactions with
other PEGylated therapeutics. To determine if vaccination with Comirnaty
increased the plasma concentration of antibodies against LNPs, we
investigated the blood plasma concentration of anti-LNP antibodies
in healthy individuals before and after vaccination with the mRNA-based
COVID-19 vaccine Comirnaty (BNT162b2). Blood samples were acquired
from 21 healthy adults before vaccination, 3–4 weeks after
the first vaccination dose but before the second dose, and 2–6
months after the second (booster) dose. The blood plasma concentration
of antibodies recognizing the LNPs was analyzed using a microscopy-based
assay capable of measuring antibody-binding to individual authentic
LNPs. No significant increase in anti-LNP antibodies was observed
after two doses of Comirnaty. The LNPs used for intramuscular delivery
of mRNA in the vaccine against COVID-19, Comirnaty, do, therefore,
not seem to induce the generation of anti-vector antibodies.