Immunization registries contain complex algorithms that predict which immunizations are valid and which are indicated for future administration to a patient. Immunization information systems and electronic medical records systems use these algorithms to provide decision support services in their applications.

HLN has extensive knowledge and expertise in developing several computerized algorithms that perform this function. Though the algorithm logic is fairly standard based on ACIP guidelines, certain jurisdiction-specific rules may be imposed based on local decisions or needs.

HLN is working now on a new, Open Source immunization algorithm product based on the OpenCDS platform. This self-contained system is accessed via a standards-based Web service interface and is designed to be a module that easily integrates with and complements third party clinical systems, such as an Immunization Information System (IIS) or electronic health record system (EHR-S). This system is being architected with technologies, such as Java, that work in diverse technical environments. It is not tied to a single rules engine or database management system.