Combining poultry vaccination with other disease control measures to combat H5N1
Vaccinating poultry, combined with several other control instruments, is an important tool in the worldwide battle against the H5N1 virus, according to an international scientific conference that ended in Verona today.
Around 400 experts reviewed the recent experiences and achievements of vaccination programmes carried out in many countries worldwide. The conference was jointly organized by the World Organisation for Animal Health (OIE), the UN Food and Agriculture Organization (FAO) and the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), with the support of the European Commission.
In 2007, the avian influenza virus has re-emerged in domestic birds in 11 countries. In Indonesia, Egypt and Nigeria, the disease has become endemic. The meeting stressed that since the beginning of the avian influenza crisis in late 2003 disease reporting and control policies have substantially improved.
To date, there are 169 confirmed human deaths due to infection with H5N1 virus. A sustained human-to-human transmission of the virus has not occurred. Fighting the disease in poultry is essential to decrease the amount of virus in the environment and thus reduce the risk of human infection and the threat of a possible human influenza pandemic.
The conference recommended that poultry should be vaccinated against avian influenza, particularly in endemic countries and when other control measures such as stamping out, movement controls of poultry and biosecurity cannot stop the spread of the virus.
A successful vaccination campaign depends mainly on the use of high quality vaccines complying with OIE standards, appropriate infrastructure to ensure the rapid and safe delivery of vaccines (cold chain), monitoring of vaccinated flocks, movement control of poultry, and adequate financial resources. Efficient veterinary services complying with OIE standards on quality and evaluation is also very important for the suspension of the use of vaccination. Any vaccination policy should include an exit strategy so that countries do not rely on costly long-term vaccination campaigns. The tools differentiating infected from vaccinated animals, such as DIVA strategy or the use of sentinel birds, are recommended in the field when possible.
There are no elements indicating human health implications related to the vaccination of poultry and to the consumption of poultry products from vaccinated animals.
The conference called upon the commercial poultry industry to reinforce its engagement in the control of avian influenza under the supervision of national veterinary authorities.
A call to international donors for the funding of vaccination in endemic countries, with particular focus on backyard poultry, was also made.
The conference urged the development and funding of more research in the following fields:
- Development of new and improved vaccines;
- Development of new vaccines that combine protection against H5N1 with the control of other poultry diseases, particularly Newcastle disease;
- Design of cost-effective delivery systems, particularly for small-holders and backyard farmers;
- Development of a vaccination decision support model;
- Data sharing of vaccination programmes conducted under field conditions
- Impact of vaccination on production consumption and trade;
- Impact of mass culling programmes on valuable poultry genetic material.
Participants of the Verona conference also proposed to develop communication strategies to improve the vaccination coverage, to avoid possible market shocks and to apply basic biosecurity measures.