Our innovative approach aims to mitigate the risk of unintended bloodstream entry of mRNA vaccines through localized vasoconstriction. By enhancing persistence within muscular tissue, we anticipate achieving nearly complete uptake of the vaccine into muscle cells, thereby preventing escape into the circulation and delivery to other tissues, such as the vascular endothelium. While the use of vasoconstrictive agents, such as adrenaline, is a well- established technique to prolong the effects of local anesthetics, its application in mRNA vaccine preparation represents a novel advancement in the field.