The scope of this subset is passive immunizing agents used in Canada (generically described, i.e. without trade name), those obtained through special access programs (generically described), and agents that have been discontinued and/or never licensed in Canada (with trade name). This content is intended to be used when populating an immunization history when the client and/or provider does not have the detail of the trade name of the agent administered OR the product has been discontinued and/or never licensed in Canada. Passive immunizing agents are used to facilitate protection against vaccine preventable infections, when vaccines are not available or are countraindicated or when vaccines have not been used before exposure to the infective agent. This subset will include concepts represented by a generic description for an agent that was previously administered to the client as may be expressed by the client or provider for an immunization history and concepts represented by the trade name for products that have been discontinued and/or never licensed in Canada. This resource is an informative value set; a normative subset containing the expanded values can be found on Canada Health Infoway's Terminology Server. Reviewers should anticipate that the representation of this valueSet will continue to evolve