Like many other vaccines, mRNA COVID-19 vaccines are recommended to be administered via the intramuscular route, in the deltoid muscle of the shoulder. Some studies posit that accidental IV vaccine administration could explain post-vaccine myocarditis and blood clots, which are rare adverse effects associated with the COVID-19 vaccines. But there isn’t enough information at the moment to establish the exact cause. The studies offer promising findings that scientists will follow up on and the knowledge gained from this research will help make COVID-19 vaccines even safer.