14 September 2001

TOVACCINATEORNOT?

VACCINATION may be a part of the national disease control policy for foot-and-mouth virus, but its value depends on the main objective and a key decision is whether animals will be slaughtered after vaccination.

How vaccination fits within any strategy for F&M depends on setting out the primary objective at the start, says Devon-based vet Richard Sibley. "Is the primary objective to control or eradicate the disease?

"For example, many diseases, such as mastitis or leptospirosis, can be controlled, resulting in low levels of incidence. But there are very few farms where these have been completely eradicated."

Another factor to consider is that vaccination tends to prolong the process of eradicating disease and no country has managed to eradicate F&M using vaccination alone, he explains.

"Any vaccination programme must have specific goals and an end point objective, such as all animals being free from virus and antibodies." Mr Sibley does not believe that any of the current proposed plans for vaccination fulfil this endpoint, using the vaccines currently available.

The Dutch recently eradicated F&M by recognising the limitations of vaccination and from the start, they planned to slaughter all vaccinated animals. All animals are now dead together with the virus, adds Mr Sibley.

Various plans offered by the BCVA include slaughtering vaccinated animals, or combinations of vaccination and slaughter. However, most of the current proposals involve allowing animals to survive after vaccination.

"It is questionable having a strategy which results in animals being alive where the presence of antibodies compromises the ability to screen for the disease. This could negate the primary objective of eradicating the virus." &#42

Vaccination tends to prolong disease eradication, says Richard Sibley.

Richard Sibley will address Dairy Event visitors in a Spotlight on Profit forum – To vaccinate or not – held in Exhibition Hall 2. See S11 for the forum programme.