AI vaccination update

Stephen Turner, Technical Director at Joice and Hill and Veterinary Consultant Phil Hammond explain why AI vaccination is unlikely to be permitted in commercial poultry until at least 2025.

The Avian Influenza virus is unstable and takes many forms, and the constant mutation leads to new strains over time. The current strain, H5N1, has become very well adapted to waterfowl – the challenge the world now has is the degree of waterfowl that migrate all over the world, and the amount of H5N1 they bring with them.

Whilst the virus cannot be controlled in wild birds, it can be controlled in commercial poultry. This is achieved through high standards of biosecurity, a twofold process, requiring both good infrastructure and effective procedures.

In the last two years, biosecurity, the cornerstone of AI control, has failed to prevent the introduction of the current H5N1 virus into poultry populations, with devastating and far-reaching effects on welfare, capacity impacts, output issues, huge cost impacts, exports market loss and trade barriers and logistical challenges.

Therefore, countries affected by AI around the world are looking at other options to try to prevent outbreaks of AI in the future, including vaccination. In the UK an AI taskforce has been set up to look at vaccination as an option.

Vaccination against AI in commercial poultry needs very careful consideration because there are pros and cons of vaccination:

The benefits are:

• Reduced mortality and clinical signs
• Reduced shedding of virus

The challenges are:

• Administration of vaccination
• Cost of vaccination
• Effect on export markets (many countries will not except imports from countries which vaccinate for AI)
• Cost, capacity, and implementation of an accepted monitoring programme

For the UK any vaccination for AI is unlikely to be permitted in commercial poultry until at least 2025. What is clear, is that if vaccination is permitted in the UK, is that a robust monitoring programme will need to be in place. This will need to operate to ensure that low levels of infection are not circulating as vaccination may not provide 100% protection.

The challenge will be determining what level of surveillance will be required, what type of testing, and where the testing will be done. This could be very costly to the industry.

In some counties AI vaccination is already practiced, namely in Asia. France will be the first EU country to allow a derogation for vaccination of geese and ducks, in the Loire region. The EU and developed poultry industries will be watching with interest to observe the challenges and benefits that this may bring. However, vaccination It is not currently permitted, and it is illegal for a veterinarian to supply AI vaccines in the UK.