All FDA-approved and emergency-use-authorized mRNA vaccines use E. coli to produce so-called starting DNA or other manufacturing materials, creating a lipopolysaccharide (LPS) endotoxin contamination risk that manufacturers test for in the finished shots.
Endotoxin has been shown to drive cardiac injury and abnormal clotting in experimental studies, and other outcomes that overlap with myocarditis, blood clots, and other serious events reported after Pfizer’s COVID-19 mRNA vaccine, raising the question of whether endotoxin was adequately excluded as a contributor.
No publicly available information tells us specifically how much endotoxin is present in finished mRNA vaccine vials.
In a January 2022 memo, the FDA reported adding a known amount of endotoxin to three samples of Moderna’s finished COVID vaccine to check whether its test could detect it.
Its test only recovered 80%, 71%, and 70% of the added activity.
Meaning 20%, 29%, and 30% of the control signal went undetected while the added endotoxin was present in the samples.
The endotoxin was still there.
FDA knew how much it had added.
Yet something in the vaccine samples prevented the test from detecting up to 30% of its activity.
FDA nevertheless accepted all three results, raising questions:
- If the test missed up to 30% of a control added after manufacture, what could it miss when endotoxin enters the vaccine’s lipid particles during manufacture?
- Why did FDA call the measured loss only “slight inhibition”?
- And why did the agency allow a complete finished-product release test to wait until after its Spikevax approval decision?
- Why have regulators and manufacturers not told us exactly how much LPS endotoxin is present in finished mRNA vaccine vials?
- Why do post-mRNA vaccination adverse events track endotoxin exposure symptoms?
Australian regulator TGA did test Pfizer’s mRNA COVID vaccine batches as “less than 5 EU/mL.”
But that means the assay couldn’t see endotoxin above a prespecified cutoff, and only after it was diluted.
It is not a count of how much total endotoxin is in each vial.
Moreover, studies examined below found that liposomes and other lipid preparations can hide over 90% of incorporated endotoxin from detection, raising the question of what happens in the lipid nanoparticles used in mRNA vaccines.
