HL7 v2 Contextual Conditions Exchange

Defines how EHR and IIS systems can exchange patient-specific Contextual Conditions through HL7 v2 and use them in immunization clinical decision support. Contextual Conditions may accompany a QBP query to influence an immediate forecast or be submitted through a VXU message for possible storage and later use, depending on IIS policy. The corresponding RSP response returns immunization evaluations and recommendations that account for the supplied conditions. The approach uses coded observations, including an OBX-based representation, for factors such as pregnancy, maternal health and vaccination, immunocompromising conditions, chronic disease, occupation, lifestyle, travel, and other medical or risk factors that can affect vaccine recommendations. It supports risk-based or context-aware immunization forecasting between EHRs, IIS, and CDS engines.