Definition of vaccine:
"a substance used to stimulate the production of antibodies and provide immunity against one or several diseases, prepared from the causative agent of a disease, its products, or a synthetic substitute, treated to act as an antigen without inducing the disease."
Is it a substance? Yes.
Does it stimulate the production of antibodies. Yes
does it provide immunity against one or several diseases? Yes. The definition of immunity is "the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells." That is exactly what the vaccine does. It provides the immune system with the ability to resist Covid.
Is it prepared from the causative agent of a disease, it's products OR a synthetic substitute, treated to act as an antigen without inducing the disease? Yes. It uses a synthetic susbstitute.
Therefore it is a vaccine. Next?