Vaccination for notifiable avian influenza in poultry.

Notifiable avian influenza (NAI) is a listed disease of the World Organisation for Animal Health (OIE) that has become a disease of great importance both for animal and human health. Prior to 2000, vaccination against NAI was discouraged and used to aid control of only a limited number of outbreaks, without reaching the goal of eradication. Pivotal work on the application of a vaccination programme aimed at, and resulting in, eradication was carried out in Italy, and was followed by other research, e.g. in Hong Kong and the United States of America. Given the spread of Asian lineage highly pathogenic avian influenza (HPAI) H5N1 to three continents, vaccination is now being used on a wide scale under different conditions, which in most cases are not ideal. Although in some countries, a lack of infrastructure and resources can greatly limit the overall success of control programmes that encompass vaccination, it is imperative that international organisations set guidelines to 'accredit' control strategies. These guidelines should include recommendations on seed strains to be used in vaccine preparations, the characteristics of the vaccine, the most appropriate field strategy to apply in the different phases of a control/eradication programme, and models of exit strategies. The availability of harmonised protocols would greatly facilitate the achievement of tangible results and would save time and avoid unnecessary wastage of resources.