The generic immunizing agent subset includes vaccines and passive immunizing agents that are currently authorized for use in Canada, those obtained through special access programs (generic description), and vaccines that have been discontinued and/or never licensed in Canada (with a tradename). This subset is a direct extension of the Canadian SNOMED CT Reference Sets developed by Canada Health Infoway. Where available, each SNOMED CT generic immunizing agent is also linked to its corresponding SNOMED CT tradename (representing the vaccine brand name), vaccine-preventable disease concept (indicating the disease the vaccine protects against), and antigen concept (representing the active ingredient triggering an immune response).