Immunization prevents over 3 million child deaths from vaccine preventable diseases such as diphtheria, pertussis, tetanus, measles and polio every year. New vaccines against respiratory and diarrhoeal diseases have the potential to prevent an additional 8 million deaths. Assuring that the existing and new vaccines are available to all children in the world is a global health priority. The health benefits of new vaccines like hepatitis B and Haemophilus influenzae type B (Hib) are indisputable. In the case of hepatitis B, over 1.2 millions deaths could be prevented each year if children and at risk adults were immunized with the hepatitis B vaccine. However, despite the clear health need and benefit, many countries have been unable to provide the 'new' vaccines, like hepatitis B vaccine, to their populations. For these countries, the limitation is not the delivery structure. Most countries now have immunization delivery structures which can provide immediate access to 80% of the country's newborns. Nor is it the vaccine availability as adequate capacity exists to meet the demand. The limitation has been the inability of governments to finance the vaccine because of a combination of factors including dependence on donors, donor policy, inadequate recognition by governments of the value of vaccines and, for some countries, the absolute price of the vaccines. The successes and failures in introducing a 'new' vaccine like hepatitis B vaccine into the world have clearly illustrated that it is economics and not epidemiology which dictates introduction of the vaccine into national immunization programmes. UNICEF and the WHO Global Programme for Vaccines and Immunization (GPV), have now developed and adopted a framework which differentiates countries based on their capacity to be financially self-sufficient for their vaccine needs. This framework forms the basis of strategies designed to co-ordinate the actions of governments, donors, agencies and vaccine manufacturers in order to ensure all countries have rapid access to affordable vaccines. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.