The Pfizer and Moderna vaccines are based on "messenger" RNA. The RNA is encapsulated in a lipid layer consisting of propylene glycol (a petrochemical).This is the biological definition of a virus. (In this case a synthetic virus.)Medical Microbiology, 4th Edition:Virus Structure and FunctionViruses are small obligate intracellular parasites, which by definition contain either a RNA or DNA genome surrounded by a protective, virus-coded protein coat. Viruses may be viewed as mobile genetic elements, most probably of cellular origin and characterized by a long co-evolution of virus and host. For propagation viruses depend on specialized host cells supplying the complex metabolic...