Avian influenza, or bird flu, stands as one of the most significant threats to the poultry industry, with a high mortality potential and severe economic repercussions. A recent INRAE report “Livestock health: challenges, research and solutions” details the efforts and advances in the fight against this highly contagious viral disease.
The devastating impact of avian influenza
Avian influenza is a viral disease affecting both domestic and wild birds. In its highly pathogenic form (HPAI), the virus can reach mortality rates of almost 100%, causing a dramatic decline in production. The most common symptoms are respiratory, digestive or neurological in nature, and in the most severe cases, birds suffer rapid deterioration of their general condition leading to death.
The 2021–2022 outbreak in France is a clear example of its devastating impact: 22 million birds were culled, at an estimated cost of €1.1 billion to the industry and €1.6 billion to public authorities.
France, a pioneer in vaccination
Since October 2023, France became the first and only European country to authorise and implement a mandatory vaccination campaign against HPAI on duck farms with more than 250 birds.
The results from the first year of the vaccination programme are very encouraging. Vaccination is estimated to have reduced the number of HPAI outbreaks in France by 96%. Between October 2023 and 2024, only 11 outbreaks were detected, despite epidemiological models having projected between 300 and 700.
Towards a universal vaccine
Despite this success, current vaccines have limitations, as they target a surface protein of the virus that mutates frequently, which may reduce their effectiveness over time. To overcome this obstacle, a group of researchers has designed a new vaccine formulation based on “universal nanoparticles”. Preliminary results show complete protection in chickens and effective blocking of virus transmission, representing a significant advance in the fight against this disease.
Improving outbreak tracing
When a case is detected, veterinary services conduct an investigation to trace the source of contamination. European regulations require a 21-day period to be covered, but this timeframe is not always appropriate for every farm.
To optimise this process, the FIRST-INF web application has been developed. This tool simulates infection on a farm, taking into account factors such as species, production type and mortality data, in order to calculate a more precise time interval for the initial contamination event. This enables veterinary services to tailor their investigations to each specific situation.
Optimising sampling to reduce costs
Disease detection and surveillance entail additional sampling and testing costs. An economist has developed an optimisation model combining a disease spread model with an economic model. The results demonstrate that it is possible to reduce the costs associated with avian influenza by a factor of 5 to 10. The study concludes that conducting small, frequent samplings (for example, 9 birds every 3 days) is more cost-effective and just as efficient as testing a large number of birds less frequently.