About Intervet
Vaccination against Avian Influenza
1 April 2003
Boxmeer, March 27, 2003 - The outbreak of Avian Influenza (fowl plague) in the Netherlands has sparked an ongoing debate about vaccination as an additional measure to control this viral disease. In principle, vaccination against Avian Influenza is possible and is administered in various countries. For various reasons, the initial response to Avian Influenza preferred in Europe entails vaccine-free control. Experience in other countries, including EU member states, demonstrates that vaccination is an effective method for preventing the virus from spreading during the outbreak stage. Intervet is involved in vaccination campaigns against Avian Influenza all over the world, which is why Intervet wishes to clarify the possibilities for vaccination below:
- Vaccination against Avian Influenza is administered on a large scale in, for instance, Mexico, Italy, Hong Kong and the Middle East.
- Intervet supplies these countries with a large share of the required vaccines.
- Vaccination protects animals against the symptoms of Avian Influenza.
- Reducing viral shed: vaccinated animals that become infected shed considerably smaller quantities of virus than non-vaccinated animals. Some animals stop shedding virus altogether. In birds that do shed virus, the quantity of virus is greatly reduced. The degree of reduction depends on such factors as age at the time of vaccination, the quality of the vaccine and the interval between vaccination and protection.
- The experience in the above-mentioned countries is positive. Vaccination made a substantial contribution to the reduction of virus circulation in the areas in question. Only few poultry farms that have administered vaccination have reported outbreaks.
- Vaccination entails the administration of inactivated vaccines that target the actual virus strain. In addition to the hemagglutinin factor that is key to protection, the vaccine contains a neuraminidase factor. Once the neuraminidase factor differs from the field strain (heterologous vaccination), it becomes theoretically possible to distinguish vaccinated birds from infected birds using a test.
- Heterologous vaccination is possible in the Netherlands, the vaccine is available. However, the associated test has not yet been developed, although the required technology is known.
- To be able to check whether the virus is circulating at a farm that has administered vaccination, non-vaccinated animals can be used to serve as “sentinel animals” at the farm. This principle has been used since the start of the inoculation campaign in Italy.
- A test has meanwhile become available for the principal virus strain in Italy, where the principle of heterologous vaccination and homologous testing is being applied with the consent of the EU. This is the first time that the EU has granted permission for the export of the meat of turkeys vaccinated against a List A disease (disease with high international priority).
- Even if the associated test becomes available in the Netherlands, an export permit from the EU’s Permanent Veterinary Committee will still be necessary.
- A number of countries have already had a vaccine bank for foot and mouth disease for many years. To facilitate the availability of the proper vaccine against Avian Influenza (also in the event of other types of the virus), it is vital to establish a vaccine bank at the European level.
It is difficult to determine whether vaccination is a desirable approach to the current outbreak of Avian Influenza in the Netherlands. It requires careful consideration of socioeconomic factors. Intervet is prepared and in a position to support this discussion based on its in-house research and experience abroad. If the authorities decide to pursue vaccination, Intervet will be able to produce a suitable inactivated Avian Influenza vaccine based on the current subtype.
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Note for the editor:
Intervet, a business unit of Akzo Nobel, headquartered in Boxmeer, The Netherlands, with sales of EUR 1.081 million in 2002, is focused on the research and development, manufacturing and marketing of veterinary products. Products include vaccines for the prevention of infectious diseases, anti-infectives, anti-parasitics and products for fertility management. All of these products are intended for use in a variety of animal species, including poultry, pigs, cattle, sheep, goats, horses, fish and companion animals. Intervet operates globally with its own marketing organizations. The company currently employs around 5,000 people.
Akzo Nobel, based in the Netherlands, serves customers throughout the world with healthcare products, coatings and chemicals. Consolidated sales for 2002 totaled EUR 14 billion. The Company currently employs approximately 68,000 people in more than 80 countries. Financial results for the first quarter will be published on April 16, 2003.
For further information, please contact:
Sabine Schueller
Communication and Public Affairs Intervet International bv
Tel: +31 (0)485 587085
Fax: +31 (0)485 585392
communications@intervet.com