KUDU RABIES VACCINE COULD EVENTUALLY BECOME A REALITY
KUDU RABIES VACCINE COULD EVENTUALLY BECOME A REALITY
Published: 18 Feb 2016
“The project revealed evidence that the modified live vaccine can be absorbed orally and can stimulate the immune system to produce antibodies,” Dr Rainer Hassel announced this great milestone achieved at the Kudu Rabies project phase 1 final review workshop hosted on Friday, 12 February 2016 at the Agra/Bank Windhoek Ring in Windhoek. The project, “Epidemiological survey of Kudu rabies in Namibia and Development of an Oral Anti-Rabies vaccine for Kudu” is commissioned by the Namibia Agricultural Union (NAU) and implemented by Agra ProVision. The project phase 1 was executed over a period of 13 months, from 1 March 2015 and will be concluded on 30 April 2016.
Opening the event, Mecki Schneider, LPO Chairperson gave a brief background on how the project was born. “It was in 2010 at an LPO event in Tsumeb where the game industry was put under the microscope for discussion. This was prompted by the 1977 kudu rabies outbreak, where about 40% of the population died at the hands of this virus,” Schneider briefly noted. He continued, “During that event, Dr Piet Basson proposed for a study to be carried out, to obtain more information about the epidemiology of rabies in Kudu. The LPO than approached Dr Hassel, through his valuable experience, as he conducted some research and published a number of articles in scientific journals after the initial outbreak during the late 1970’s. Furthermore, the LPO appointed Dr Libertine Amadhila as patron of project.” In conclusion, Schneider reminded those in attendance that Kudus are very important resources that brings in substantial income and good foreign exchange.
Dr Rainer Hassel, the project leader gave a presentation on the background, implementation and current status of the project. Rabies is a fatal viral disease and can often be transmitted from one species to another. “Animals can be vaccinated against rabies. However, vaccination of free roaming wildlife using traditional vaccine requires the use of helicopters and darting, making the process a very costly exercise with a high chance of missing individual animals. It is for this reason that the research explored alternative vaccination methods, drawing best practices successfully achieved in parts of Europe to vaccinate foxes using an oral bait,” said Dr Hassel, as he explained the essence of the project.
The project aimed to improve the understanding of the epidemiology of rabies in kudu in Namibia, while investigating the (possible) occurrence of rabies in the Kudu population. Furthermore, the project tested a hypothesis to prove the horizontal spread of rabies by direct contact between kudu. The ultimate goal of the project is to develop a practical method to control Kudu rabies.
According to Dr Hassel, the project achieved positive results including the successful development of suitable baits and the successful completion of the intra-muscular vaccine trails which exceeded the set objectives. The results revealed that the transmission trials performed as part of the project were not able to prove that transmission of rabies from infected to non-infected kudu by direct contact did occur.
The main goal of the research project was to provide viable alternatives for an effective practical method of oral vaccination of kudu against rabies. Dr Hassel explained the procedure to establish the practical method for kudu. He said: “the project tested two methods of vaccination using two different types of vaccine: oral and intra-muscular vaccine, to determine whether the vaccinations achieved protection against animals infected with rabies. For the oral vaccine group, the results indicate that 7 out of 10 animals vaccinated by direct oral application of a modified live vaccine developed clinical symptoms consistent with rabies and died after a very short time, after being challenged with a high dose rabies virus. Whereas for the intra-muscular vaccine group, 9 animals were vaccinated with a commercial inactivated vaccine and they all survived the high dose of rabies virus challenge subsequently.” Dr Hassel interpreted these results stating that intra-muscular vaccination protects 100% of vaccinated animals against rabies infection, while oral instillation of the modified live virus currently does not protect the kudu population using the method applied in the trials. The method of oral application of the vaccine therefore needs to be changed and improved in order to induce an immune response in the vaccinated animals that will protect them against the infection.
Dr Hassel concluded by saying that most activities were successfully completed with substantial results obtained. There is an indication that Rabies is becoming more of a problem in Namibia. Therefore, this warrants the continuation of the project with phase 2. Dagmar Honsbein, General Manager of Agra ProVision shared Dr Hassel’s sentiments when she presented the details of the proposed phase 2. Honsbein said Phase 2 will be implemented with the main objective 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. The proposed phase will cost an estimated amount of N$ 2.8 Million (Two million and eight hundred Namibian dollars).
Background of Rabies in Namibian Kudu In the late 1970’s to early 1980’s, a rabies epidemic occurred in Namibia within the Kudu population, leading scientist to believe that a non-bite oral transmission between Kudus was taking place. The first epidemic lasted about ten years, followed by a period of only sporadic cases. However, the incidents in Kudu increased again in 1999, and since 2002 has reached epidemic proportions again. This serious disease not only continues to pose a threat to the kudu population, but also threatens to infect commercial livestock. The negative economic and health impact that a rabies outbreak can have on farming community of Namibia can be considerable.