Pfizer examined possible ways its COVID-19 vaccine causes heart inflammation, a newly disclosed document shows.
The company in a 2022 white paper acknowledged that its vaccine, BNT162b2, may be causing myocarditis, or heart inflammation, and a related condition called pericarditis.
Pfizer scientists claimed that the inflammation was likely not the result of direct cardiotoxicity, but did not rule out several other possible mechanisms, including that it stemmed from immune activity.
The immune system may be triggered by lipid nanoparticles, which in the messenger RNA (mRNA) shot deliver the spike protein, the document says.
“Although the BNT162b2 mRNA vaccine is optimized to reduce its detection by the innate immune system through the addition of nucleoside modifications and minimizing double-strand RNA impurity, it is possible, especially in certain individuals with genetic predisposition and underlying conditions that the immune responses to mRNA may not be sufficiently turned down and drive the activation of an innate and adaptive immune response,” they wrote in the 48-page white paper….