Vaccines can be constituted of agents of **, of inactivated agents of **, of inactivated toxins or of fragments of the infectious agent.
Examples of some vaccines and their type of antigenic agents are: BCG, inactivated tuberculosis bacilli; antitetanic vaccine, inactivated toxin; antidiphtheric, inactivated toxin; antipolio Salk, **** poliovirus; antipolio Sabin, attenuated (inactivated) poliovirus.
