Practicalities of the implementation of a vaccination campaign for avian influenza.

Emergency vaccination for avian influenza (AI) infections caused by viruses of the H5 or H7 subtypes has been used in several instances over the past years. It has been applied primarily in the chicken and turkey industry with the general objective of controlling, and in some instances eradicating, infection. The use of vaccination as a tool to eradicate AI requires the enforcement of a coordinated set of control and monitoring measures. In fact, only certain attempts at eradicating AI with the support of vaccination have been successful, and the outcome of the vaccination campaign has been shown to depend greatly on effective application of the field strategy that complemented the vaccination program. While it is taken for granted that the product and companion diagnostic test are suitable for that given situation, a monitoring system must be in place to promptly identify whether vaccinated birds have been field exposed, and the latter should be dealt with in an appropriate manner, avoiding the spread of infection to other premises. Prophylactic vaccination could also become a tool for AI management in the European Union, provided that its application is based on a systematic assessment of AI risk. The correct use of this tool can be a valuable support for the control of AI in poultry, with the added value of limiting the economic losses to the industry and to the taxpayer. Eventually, this will also reduce human exposure to potentially dangerous viruses.