This class represents an assertion that an administration of a vaccine to a patient did not occur. Such information is useful when an administration would normally be expected, and this class serves to document that it indeed did not occur (as opposed to leaving the medical record blank). This class may contain (via associations) information regarding why the administration did not occur such as documentation of an Exemption, a Contraindication, or of an established Immunity Status. "Describes the event of a patient being administered a vaccination or a record of a vaccination as reported by a patient, a clinician or another party and may include vaccine reaction information and what vaccination protocol was followed." - HL7 FHIR, Immunization