Vaccination to Control Bluetongue in Cattle and Sheep

The presence of Bluetongue in Mediterranean Europe caused a considerable economic impact on the countries affected. To limit direct losses and in an effort to minimize the circulation of Bluetongue virus as well as to allow the safe movement of animals, governments in affected countries vaccinated livestock.

In order to maximise the benefits of bluetongue vaccination, it is recommended that:

• Vaccination is carried out prior to the beginning of the risk period. This is defined by the start of Culicoides activity.
• Mass vaccination is implemented within the risk area. Although sheep are the animals that are worse affected by the disease, vaccination should target both sheep and cattle to reduce the risk of further spread of the virus.

Inactivated BTV vaccines

Inactivated vaccines against BTV‑2 and BTV‑4 have been used in the field after the emergence of BTV in Corsica, Spain, Portugal and Italy. The use of inactivated vaccines has been effective in disease control in these areas.

The efficacy of inactivated BTV vaccines has been established under experimental conditions. Given the disadvantages of modified live vaccines and the regulatory difficulties to license genetically modified vaccines, at this moment, Bovilis BTV-8 is a feasible option for use in northern Europe.

Follow the links in left navigation menu for more information about an inactivated BTV-8 vaccine.

Live vaccines used in Mediterranean Europe

In southern Europe modified live vaccines were used because they were the only thing available and the disease needed controlling.

However, modified live vaccines have a number of disadvantages:

• Not licensed for use in the EU.
• May cause teratogenic effects therefore are not recommended for use in pregnant animals.
• Vaccine virus can be transmitted by Culicoides to unvaccinated animals.
• In some situations it appears that the vaccinal strain can recombine with field strains to create yet new strains or serotypes.