The international community is confronted with a crisis caused by the unprecedented global spread of highly pathogenic avian influenza and its consequent scientific, economic, political, social and ethical challenges. Control strategies based only on the application of sanitary measures and the culling of animals that are infected or suspected of being infected have proven insufficient to avoid the propagation of infection. The OIE, together with the FAO, recommend the strategic use of poultry vaccination in certain situations as part of an overall integrated strategy to control the disease. This volume presents the proceedings of a scientific conference co-organized by the OIE, FAO and the Istituto Zooprofilattico Sperimentale delle Venezie with the support of the European Commission. The conference brought together scientists, representatives of government authorities, industry and other stakeholders to review current methods and recent experiences in the use of vaccination as a means to control and prevent losses due to avian influenza. They also scrutinized international standards and regulations for vaccination and considered the implementation of vaccination programmes. The proceedings include presentations on the experiences made in various parts of the world and the challenges and constraints faced by developing countries in implementing effective vaccination campaigns. Other contributions provide guidance to decision makers concerned with planning vaccination campaigns and up-to-date information on developments in avian influenza vaccines, their efficacy, their performance in different avian species and on strategies of differentiating infected from vaccinated animals as well as their application.