The Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention (CDC) has been increasing the size of the population for whom influenza vaccine is recommended to reduce the substantial and persistent annual health burden of influenza. Realization of current and future public health influenza immunization goals requires assuring vaccine supply will be adequate to meet demand. This has posed distinct challenges for the many stakeholders in the influenza vaccine program--government agencies, federal, state, and local policymakers, vaccine manufacturers and distributors, and the medical community--each of whom must make critical decisions in a constantly shifting environment. Factors such as the yearly changes in influenza virus strains, the complicated vaccine production and distribution process, revisions in vaccination recommendations, and changing demographics can all affect the delicate balance between supply and demand. While vaccine shortages and delays have been well-publicized concerns in the recent past, there has been a marked increase in supply in the past several years, with substantial growth in supply expected in the future. The primary issue today is to strengthen the demand for the influenza vaccine, which would in turn help ensure the continued availability of the vaccine to reduce disease burden. A number of strategies are discussed, including increased efforts to publicize and fully implement current CDC recommendations and to offer influenza vaccine beyond the typical vaccination season of October and November, because in the great majority of years, vaccination into January and beyond will still provide health benefits.