AS 4700.5:2002 pdf free.Implementation of Health Level Seven (HL7) Version 2.3.1 Part 5: Immunization messages. 5 USAGE OF IMMUNIZATION MESSAGES Immunization messages are intended to assist direct communication of immunization information between the provider and the registry. At the time that the actual immunization is administered, the immunization message is sent by the provider to the registry to update the...