THE Ovine Johne¹s Disease vaccine Gudair is now available to WA sheep breeders after Pfizer Australia completed several training sessions with local veterinarians last week.
The training, mainly to alert users to handling safety issues, involved about 20 vets in rural areas and was a prerequisite for those intending to distribute the vaccine in WA.
Pfizer¹s NSW regional business manager Mac Paterson said he expected the vaccine would sell for $1.90-$2 a dose. The price immediately sparked concerns by sheep breeders at an information session at Katanning last week that vets would charge excessive amounts over and above the $1.60-$1.70 currently paid in eastern Australia.
The whole-of-life vaccine, which triggered a cellular immune response in animals, was a component in the new national OJD assurance based credit (ABC) scheme to come into effect from July 1.
Vaccination would be voluntary for flock owners and neither Mr Paterson or Agriculture WA senior veterinarian Fiona Sunderman were prepared to recommend flock vaccination but encouraged sheep producers to make a decision in consultation with their approved SheepMAP veterinarian.
Dr Sunderman said the vaccine delayed the development of the disease and reduced the amount of bacteria shed but was not a cure.
Its effectiveness was cumulative as subsequent generations were vaccinated resulting in continual reduction of the amount of bacteria shed onto pastures. The vaccine was a tool recommended for use in conjunction with changes to stock and grazing management practices to reduce losses due to the disease.
Gudair, an inactivated vaccine made in Spain since 1994, was administered as a 1ml dose to lambs from 4-12 weeks of age but it also could be economic to vaccinate whole flocks including adult sheep if infected.
Blood taken from vaccinated sheep tested positive for OJD but pooled faecal culture (PFC) tests of uninfected vaccinated sheep were negative.
For this reason it was necessary to identify treated animals with an approved National Livestock Identification Scheme (non-electronic) year colour-coded ear tag carrying the property¹s registered brand and a ³v² in a circle if the stock was being sold to buyers other than a processor.
Mr Patterson said vaccination guidelines also warned farmers to seek medical attention if accidental self-injection occurred, saying it had some localised but serious side effects for humans.
An intensive five-year trial in the central tablelands in NSW scheduled to end soon had compared the effects of vaccination on three high-prevalence properties.
Using 200 vaccinated and 200 untreated controls run together in a high challenge situation they found the control group was shedding bacteria by nine months of age and there were 18 deaths in sheep from 18-21 months of age. In the vaccinated group shedding didn¹t start until 14 months and only one death occurred in the same period.
After four years there had been 75 deaths in the controls and seven in the vaccinated group.
Once a vaccination program was started it took several years before losses were reduced and for this reason it was recommended the program start early - when death rates were only about 2pc.