Introduction
Gudair® vaccine is the only vaccine registered in Australia for the control of Ovine Johne's Disease (OJD) in sheep. Gudair® vaccine is also registered for use in goats.
Ongoing trial work has shown that the vaccine reduces the level of clinical disease and mortalities, and delays and reduces the shedding of OJD bacteria in faeces. Used over several years, it will help reduce the potential for further spread from contaminated pastures.
The vaccine is inactivated (killed), meaning that it will not introduce OJD into a sheep flock.
It is most effective if administered to sheep before being exposed to the disease. Although sheep of any age can be vaccinated, the risk of OJD is considered to be very low for sheep classified as 'approved vaccinates'.
Approve vaccinates are:
sheep vaccinated at less than 16 weeks of age; or
sheep vaccinated after 16 weeks of age where the flock is currently participating in the Sheep MAP
or the flock has undertaken a negative Faecal 350 test in the last 2 years preceding the vaccination
or has a current Negative Abattoir 500 status at the time of vaccination.
Reasons for using the vaccine
For flocks with OJD, the vaccine provides an important management tool for controlling the disease.
The vaccine should be used in flocks considered at-risk of infection from OJD to minimize spread of the disease if it is introduced. Examples of at-risk situations include flocks that adjoin an infected property or flocks that buy in sheep of unknown OJD status.
In Tasmania, the disease is widespread and it is recommended that all sheep producers vaccinate lambs they will retain on their property after 12 months of age. Vaccination of adult sheep can be considered where the risk of infection is high.
Identifying vaccinated stock
All sheep and goats that are 'approved vaccinates' should be identified at the time of vaccination with a
National Livestock Identification Scheme (NLIS) sheep ear-tag bearing a 'V' symbol.
These tags bear your Property Identification Code (PIC) and the NLIS logo on one side. For sheep and goats that receive the Gudair® vaccine, a 'V' symbol should be printed on the opposite side to the PIC and logo. You can also choose to have a serial number on the same side as the 'V'.
If you are authorised for NLIS access please contact your local rural supplies agent to obtain NLIS tags. If you do not have NLIS access, contact the NRE Tas Registrar of Brands on tel. (03) 6165 3777, or email nlis.tas@nre.tas.gov.au.
Purchasing vaccine
In Tasmania, the vaccine is only sold by accredited private veterinary practitioners and rural merchandisers.
A single dose of 1ml of vaccine provides lifetime protection. The vaccine is available in 100ml or 250ml packs.
It is legal for small flock owners to share a vaccine pack. Needles should be changed between flocks.
Use of vaccine
The product must be used in accordance with the manufacturer's instructions.
A single dose of 1ml of vaccine for the life of the animal is given by subcutaneous injection, ie under the skin. The only recommended site of vaccination is high on the neck, just behind and below the ear. Do not inject along the midline of the neck or into the base of the ear.
Good restraint of animals whilst vaccinating is important. Lambs should be vaccinated while restrained in a lamb marking cradle. Weaners, hoggets and adult sheep that are to be vaccinated in a race should be packed tight with their heads held high to ensure the vaccine is delivered at the correct site.
The vaccine may cause a nodule or swelling to occur at the site of injection in some animals within a couple of months of vaccination. These lumps have been known to persist in 20 - 25% of vaccinated animals for at least four years. Vaccination high on the neck reduces the risk of this nodule downgrading the value of the carcass at slaughter.
Safety
It is important to read the product insert prior to use of Gudair® vaccine.
Accidental self-injection with this vaccine can cause severe and persistent reaction in some people. Before vaccinating please have a look at the following:
Seek advice from a doctor immediately if accidental self-injection occurs.
A 1ml vaccination gun with a retractable needle cover is available from retailers of Gudair® vaccine. This type of vaccinator reduces the risk of needle-stick injuries (see below).
In a 2002 survey undertaken in New South Wales, most incidents of self-injection were found to have occurred when the person was moving amongst sheep in races or climbing into yards, suggesting that the vaccination gun must be held in a safe position at all times.
Disposal of vaccine
A person must not dispose of unused Gudair® vaccine other than as directed on the label.
Other issues
The use of Gudair® vaccine, including identification of vaccinated stock, may be subject to annual or random auditing by inspectors.
It is recommended that before embarking on a vaccine program, producers discuss the pros and cons of the use of Gudair® vaccine with their veterinarians.
Video on safe and effective vaccination
Note: Since the making of this video Bruce Jackson has retired from NRE Tas.