Immunization registries can be building blocks for national health information systems.

Electronic health records and health information exchanges are necessary components of the information infrastructure to support a reformed health care system. However, they are not sufficient by themselves. Merely summing data from electronic health records together will not provide a comprehensive picture of the population, which is essential for tracking disease trends and treatment outcomes. Public health information systems such as immunization registries are an essential component of the information infrastructure and will allow assessment of the impact of changes in health care on the population as a whole.