[The Pan American Health Organization's Revolving Fund for access to vaccines: 43 years responding to the regional immunization programO Fundo Rotativo para Acesso a Vacinas da Organização Pan-Americana da Saúde: 43 anos respondendo ao Programa Regional de Imunizações].

The Pan American Health Organization's Revolving Fund for Access to Vaccines (the Revolving Fund) is a shared pool of funds for the procurement of vaccines, syringes, and cold-chain equipment for the Member States of the Organization. With a view to evaluating the results obtained during the Revolving Fund's operation and analyzing its contributions to achievements in immunization, a review was conducted of historical documents and grey literature related to the Fund's history and current processes, as well as data from platforms fed by countries' annual reports, with reference to growth indicators, burden of vaccine-preventable diseases, introduction of new vaccines in the Region of the Americas, and lessons learned. In its 43 years of operation, the Revolving Fund has grown and contributed to the introduction of new vaccines, and the Region has made rapid progress in the field of immunization. However, several countries and territories in the Region have not yet introduced certain vaccines due to their high cost and the economic impact of sustainably administering them. The requirement to obtain the lowest possible price and to set a uniform price for all participating Member States has been instrumental in the Revolving Fund's contribution to the vaccination goals of national immunization programs, and for timely planning of demand, accompanied by technical advice. An interprogrammatic approach and the planning of auxiliary inputs are key to the success of the programs. Pandemic preparedness, regional vaccine production, and the protection of national budgets for sustainable procurement of high-cost vaccines are current and future challenges.