Message Structure
14 segments
R RequiredO Optional Choice
MSH
R1PID
R1PD1
O1NK1
O*PATIENT
O1PV1
R1PV2
O1INSURANCE
O*IN1
R1IN2
O1IN3
O1ORDER
O*ORC
O1RXA
R1RXR
O1OBSERVATION
O*OBX
R1NTE
O*Used by Events:V04VXU - Unsolicited vaccination record update