Vaccine mRNA Can Be Detected in Blood at 15 Days Post-Vaccination.
Level 4 - case-series / case-control
Small prospective observational cohort without a comparison group, alongside in vitro cellular assays.
PubMed 35884842 · doi:10.3390/biomedicines10071538
What was done
The authors used qPCR to track circulating BNT162b2 vaccine mRNA in the blood of a small cohort of healthy individuals across multiple post-vaccination time points. In addition, transmission electron microscopy (TEM) was performed in vitro on human K562 leukemic cells and primary blood mononuclear cells exposed to BNT162b2 to assess lipid nanoparticle (LNP) uptake and SARS-CoV-2 spike protein expression.
What was found
Vaccine-associated synthetic mRNA persisted in systemic circulation for at least 2 weeks (15 days). In vitro TEM demonstrated morphological changes suggestive of LNP uptake, with only a small fraction of K562 leukemic cells presenting surface spike-like structures. The abstract reports no exact participant counts, cycle threshold values, or quantitative mRNA concentrations.
Why it matters
This study provides evidence on human pharmacokinetics showing that vaccine mRNA delivered via lipid nanoparticles enters the systemic circulation and persists in blood for at least two weeks.
Limits
The abstract does not state the sample size (only noting a 'small cohort') and provides zero numerical data or statistical estimates. It lacks long-term follow-up beyond two weeks, does not assess whether circulating mRNA translates to active systemic protein production in vivo, and relies partly on in vitro leukemic cell lines.
Cited by
- context Following mRNA vaccine injection into muscle cells, translated spike protein levels peak after 24 hours, vaccine mRNA has a half-life of 48 to 72 hours, and the lipid nanoparticle vehicle degrades within hours.