Scientists finally mapped out exactly how long those mRNA vaccine pieces stay intact in your blood.
medRxiv · March 17, 2026 · 10.64898/2026.03.13.26348310
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The Takeaway
While millions have been vaccinated, the precise rate at which the vaccine's mRNA and its protective lipid shell break down in the human body was largely unknown. This study quantified these kinetics, revealing that the Moderna vaccine's mRNA breaks down twice as fast as the Pfizer version in the blood.
From the abstract
mRNA-lipid nanoparticle (LNP) vaccines are detectable in human blood after vaccination, but platform-specific differences in systemic persistence and transcript integrity remain poorly defined. We analyzed serial blood samples from 73 participants receiving Moderna mRNA-1273 (three formulations), Pfizer/BioNTech BNT162b2, or an investigational receptor-binding domain (RBD) mRNA vaccine (three different doses). Using droplet digital polymerase chain reaction (ddPCR) assays, we quantified total an