Pfizer, on its website, confirms its COVID-19 vaccine contains modRNA: "ModRNA stands for nucleoside-modified messenger RNA and in the synthesis of the RNA used in this vaccine platform, some nucleosides, which are important biological molecules that constitute DNA and RNA, are replaced by modified nucleosides to help enhance immune evasion and protein production." The company says modRNA instructs the cells to produce desired proteins. Yet the Centers for Disease Control and Prevention (CDC) states on its website (pdf) that mRNA COVID-19 vaccines are "made of mRNA," or "messenger RNA." According to the agency, the mRNA in COVID-19 vaccines such as Pfizer and Moderna is created in a laboratory and teaches cells how to make harmless pieces of spike protein that trigger an immune response inside the body. The mRNA from mRNA-based vaccines is broken down within days after vaccination and eliminated from the body. In its description of mRNA and how COVID-19 vaccines work,