subcellular structures [13]. The development of such therapeutics is anticipated to redefine clinical pathways, including for non-communicable diseases. However, are these therapies ready for worldwide application in their present molecular form?The question has been asked before, often in relation to the potential toxicity of lipid formulations used in the past, especially as part of the delivering cancer therapeutics [14,15]. However, in the following sections, we take a closer look at a novel perspective, namely the mRNA vaccines' structure and composition and at their unintended biological consequences derived from pathological cell-cell fusion. Messenger RNA Vaccines, an OverviewTo elicit the formation of neutralizing antibodies, exogenously administered mRNA must avoid two key obstacles: Hydrolysis by extracellular RNAases and recognition by cytosolic innate immune sensors, including toll-like receptors (TLRs) and retinoic acidinducible gene I (RIG-I) protein [16,17]. The former is accomplished by hiding the nucleic acid backbone into LNPs, while the latter by attaching nucleobases, such as N1-methylpseudouridine (m1Ψ) to the mRNA [18,19] (Figure 1). The coding region of the mRNA is flanked by two untranslated regions (UTRs) followed by a polyadenylated (polyA) tail at 3' and a cap at 5' for