Windhoek
Namibia is edging closer to a possible world first for developing an anti-rabies vaccine for kudu after a research team concluded that the results achieved so far in the Rabies in Kudu Project fully justify the implementation of the second phase in a quest to develop such a vaccine.
A quarantine camp was erected on the farm of Peter Clausen in the Otavi area where the first phase was successfully completed. The current stock of all equipment, drugs, medicines and consumables is expected to be sufficient to last until the conclusion of the project.
Explaining the results of the first phase, team leader of the project, Dr Rainer Hassel, says all nine kudu of the Intramuscular Vaccine Group that were vaccinated with a commercial inactivated rabies vaccine, “Rabisin” (Merial), survived rabies after developing anti-rabies bodies.
The objectives of Phase 2 will be the completion of the successful development of an effective and practical oral vaccination method, and the long-term evaluation of the efficacy of the intra-muscular vaccination with an inactivated vaccine.
The activities to achieve this objective will include the capture and translocation of test animals, collection of serum samples of all animals and determination of serum antibody titers, as well as the inclusion of SPBN GASGAS vaccine in two different types of bait.
The vaccine will be incorporated in a suitable container included in the bait. Feeding the bait to two different groups of 9 and 10 animals respectively, drawn from the surviving animals of the previous groups 1 and 3. One group will be fed the vaccine containing bait at a rate of 5 pieces per animal daily for 8 days.
The second group will be fed the bait at a rate of five pieces per animal every second day for eight days. The rationale is that the animals will chew the bait, causing the release of the vaccine in the oral cavity and exposure to the oral mucous membranes. Repeated administration of small doses of vaccine will reduce the loss of vaccine through spillage.
All surviving animals of the previous Group 2 will be used for this phase.
After six months an attempt will be made to locate and immobilise all the surviving animals to collect serum samples. All serum samples will be tested by FLI, using ELISA and RFFIT methods to determine presence and titers of antibodies. The duration of these activities will be six months.
The first phase of the project was completed on February 12. The intra-muscular vaccine trials, including challenge infections, have been completed successfully with excellent results. The preliminary oral vaccine trials, including challenge infections, have been concluded with moderate results.
The bait trials have been completed successfully rendering excellent results. Evaluation of the epidemiological survey is still in progress.
Artificial transmission trials are still in progress. The serological survey has been completed successfully rendering unexpected results. The successful completion of most activities and achievement of most objectives with the results obtained warrants the continuation of the project with the only objectives to develop an effective and practical method of oral vaccination of kudu against rabies and to determine the duration of immunity of animals in the intra-muscular vaccine group.
Namibia spends N$600 million annually to import vaccines and pharmaceuticals for its livestock sector.