This article summarizes principal findings and recommendations of the National Vaccine Advisory Committee 2007 Progress report on Immunization Information Systems (IIS). Considerable progress has been made in each of the four primary objectives of the IIS: ensure appropriate protections of privacy and confidentiality for individuals and security for information included in the registry; ensure participation of all immunization providers and recipients; ensure appropriate functioning of registries; and ensure sustainable funding for registries. In addition, IIS use has been extended to deal with adolescent/adult immunization, preparedness, vaccine shortages, health information exchanges, and electronic medical records. Notwithstanding the progress, several factors impede smooth achievement of the 2010 goal. The three most critical are difficulties in exchanging information among different information systems, difficulties in exchanging information across state lines, and ensuring sustainable funding for registries. The committee has made a number of recommendations to address these issues.