Pro-poor vaccine-based control of East Coast fever |
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| Better control of East Coast Fever (ECF) in cattle in East and Central Africa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
In Central and East Africa, work is ongoing to give producers access to effective vaccines that will protect their cattle against the devastating disease East Coast Fever. This could greatly improve the lives of poor livestock keepers, as East Coast fever is responsible for about half of all calf deaths in pastoral and agro-pastoral production systems in these areas. One thrust of these efforts is the promotion of the infection and treatment method (ITM), which has already been shown to be effective but which has not been widely taken up for a variety of reasons. Other efforts are concentrating on the development of next-generation vaccines that are safer, costs less, and are easier to transport. Project Ref: AHP14:
Research Programmes:
Relevant Research Projects: · R8208: Decision support for risk management strategies of tick-borne diseases within sustainable pastoral systems
· TAG 376: Enhancing the impact of immunisation against East Coast Fever with an improved sub-unit vaccine on the smallholder dairy sector in eastern Africa · TAG 596: Infection and Treatment Method at the Crossroads: Project Addressing Key Constraints to the Sustainable Delivery and Adoption of Immunization Against East Coast Fever for Poor Livestock Keepers in Eastern Africa
· R8042: Integrated Control of East Coast fever constraining livelihoods of smallholder farmers in sub-Saharan Africa. Collaborators include:
· Support for Deployment of Live Vaccine against ECF - R6725H. In partnership with the National Veterinary Research Centre, Muguga, Kenya.
The cluster of outputs were aimed at better control of one of the most devastating cattle diseases in East and Central Africa; East Coast fever (ECF). Some outputs relate to better application of an existing vaccine while others relate to the development of an improved vaccine. ECF is a disease of cattle widespread in 11 countries in East, Central and Southern Africa. It is transmitted to cattle through the bites of the tick Rhipicephalus appendiculatus. Of the estimated 40 million cattle in this region, about 26 million are at risk of ECF. ECF is responsible for about half of all calf deaths in the pastoral and agropastoral production systems and is largely responsible for the lack of upgrading of indigenous breeds in areas where it occurs. Current ECF control strategies include regular use of acaricides or treatment of sick animals both of which have been unsuccessful. The infection and treatment method (ITM) of immunisation was developed in the mid 70s. It involves inoculation of cattle with live parasites together with a long-acting antibiotic that leads to mild reaction and full immunity against subsequent infection. Although ITM is highly effective it has some limitations including the need for a cold chain, high cost and concerns of safety. There is therefore, a need to develop an improved vaccine. Outputs related to the impact of ITM: Information has been gathered on the impact of ITM in different cattle production systems. Concerns related to the safety of the vaccine and long-term biological impacts have been addressed thus allowing policy changes that have promoted the use of ITM as central strategy for ECF. Availability of molecular tools for ECF parasite characterisation have assured policy makers and service providers that long-term impacts of the use of a live vaccine across the regional can be monitored. Outputs related to commercialisation initiatives. Research based evidence from pilot studies have demonstrated the commercial viability of ITM. This has influenced policy-makers to allow the use of the vaccine in Kenya, Uganda and Tanzania. It has also created interest by the pharmaceutical companies in investing in the production and distribution of the vaccines. The Agrochemical Association of Kenya (AAK) and GALV-Med have shown interest in creating public-private partnerships with research institutes to provide access by the livestock farmers to ITM in the regional. Outputs related to the next generation vaccines: The need to develop recombinant vaccines for ECF has arisen from the limitation of the current live vaccine with regard to safety, deliverability (cold chain) and costs. The DFID supported research on recombinant ECF vaccines has led to the following key outputs:
The outputs focus on livestock and livestock products ECF vaccine research represents an excellent example of a rational approach to development of robust vaccines against complex pathogens. Central to this approach is the availability of a strong platform of immunological information on host protective immune mechanisms and a good knowledge of the biology of the pathogen. The technical success of developing a subunit vaccine against ECF is hinged on excellent progress in identification of antigens which are targets of the well-characterised host immunity based on CD8 T cell responses. Equally important, is the identification of an effective vaccine formulation which will induce such immunity against lethal challenge. The availability of a T. parva genome sequence, a good quality schizont cDNA library and availability of a high throughput antigen screening system have underpinned the success in identifying bonafide vaccine candidates. By virtue of their intracellular location in nucleated cells, pathogens that cause malaria, TB, tropical theileriosis and heartwater (all major killers) are targets of the CD8 T cell immunity similar to that in ECF. It would therefore be expected that similar strategies could be employed to identify target vaccine candidates. It is of great benefit that the genomes of all these pathogens have been sequenced and are either fully annotated and published. As the project is using the same vaccine formulations (DNA/MVA prime/boost) which are being evaluated in human clinical trials for TB and malaria, opportunities for information exchange are being exploited towards the realisation of global public goods. Immortalisation of Theileria-infected host cells is reminiscent of a cancerous state. Human cancer studies have shown that CD8 T cells are also important in resolution of tumors suggesting that similar vaccine approaches can be employed. In addition, the availability of a fully annotated T. parva genome sequence will inform studies on the transformation of the infected host cell which might provide clues to mechanisms in cancer. The publication of these data would be yet another example of global public goods.
Although most fail points for commercial and sustainable delivery of ITM have been addressed through the outputs described above there remains some constraints to this process. Linkages of these outputs with trade issues to allow for non restrictive trade among the countries in the region would add value to this output. Although commercialisation has been identified as best option of the sustainable delivery of this technology this does not benefit all segments of the poor farmers equally. Linking this output with other support to disadvantaged farmer groups such as micro credit schemes would greatly add value to the output. Since ITM has such a dramatic reduction in calf mortality, value would be added by addressing marketing constraints for livestock and livestock products so that farmers fully benefit from reduced losses through higher offtakes. Linking this output with a marketing project or livestock producer organisation would add value to the output. The output would complement and could be clustered with the AHP outputs Decision support for diagnosis: Simple decision support tools for diagnosis of endemic diseases in Africa and Treatment of cattle to eliminate the animal reservoir of T.b. rhodesiense. How the outputs were validated: Extensive validation of the ITM technology to determine safety, efficacy and impact and improve deliverability has been carried out at three levels; laboratory experimentation, controlled field immunisation, pilot projects with partial cost recovery and commercial delivery . Laboratory trials on efficacy and safety and identification of immunising parasites have been conducted by the former East Africa Veterinary Research Organisation (EAVRO), the Kenya Agricultural Research Institute (KARI) and the International Livestock Research institute. Safety and efficacy has been determined through experimental challenges of immunised cattle, with a range of parasites to asses the spectrum of protection with non-immunised cattle as controls. Controlled field immunisations, to asses efficacy and safety where the level of challenge is based on comparison of disease in immunised and non-immunised cattle have been conducted in Kenya, Malawi, Rwanda, Uganda, Tanzania, Zambia, Zanzibar, Zimbabwe and Rwanda. Validation has been carried out on both single (Kenya, Rwanda, Zambia, Zimbabwe) of local parasite isolates and a mixture of parasite stocks (Kenya, Malawi, Uganda, Tanzania, Zambia). Most of the trials have been conducted by national agricultural research systems with support from bilateral and multilateral donors. For instance in Kenya, KARI with support from ODA and later DFID carried most of the field trials. In Uganda the Livestock Research Institute (LIRI) with support from DANIDA conducted the trials. In Zanzibar, ILRI with funds from ODA conducted some the field trials. In Tanzania the Integrated Ticks and Tickborne disease project with support from Dutch and Austrian government supported most of the filed trials. Pilot field immunisation have been carried out in most of these countries to assess efficacy, safety, spectrum of protection and impact of ITM. Most of these have been supported by donor project. In Southern Africa (Malawi, Zambia Zimbabwe, Tanzania) an FAO regional project on ECF immunisation conducted most of these projects. In east Africa bilateral donor supported the work (e.g DFID in Kenya, DAINIDA in Uganda). Commercial validation of ITM has been carried out in Kenya and Tanzania. In Kenya Coopers Kenya limited, a private pharmaceutical company was given the exclusive rights to deliver the single stock based ITM vaccine but due to geographical and production system restriction the company was unable to sustain the delivery. More recently a non governmental organisation, Veterinares sans Frontiers Germany (VSF-G) in collaboration with KARI and ILRI has established a successful commercial delivery in the Maasai pastoral areas. In Tanzania commercial delivery by Vetagro, Tanzania, in pastoral areas has been going for about three years with more than 100,000 cattle immunised this way. Nearly all production systems have been involved in these trials. In Kenya and Zimbabwe the pilot field trials and commercial delivery were initially in smallholder dairy farms and large scale commercial farms. Recently commercial delivery has gone into pastoral production systems. In the rest of the region most of the trials have been in pastoral and agropastoral production systems with indigenous breeds. Where the Outputs were Validated: In Kenya validation with the single parasite stock was carried in between 1992 to 2000 at 22 sites in all parts of the country including Coast, Central, Eastern, Rift Valley, Nyanza and Western provinces. Most of the trials were in smallholder dairy rain fed highland systemsand in periurban dairy farms but a few were also conducted in large scale commercial dairy farms. More recent trials have since gone to pastoral extensive productions systems which are semi arid livestock systems In Uganda trials were conducted between1990 to 2002 in 29 districts covering all parts of the country. The majority of the trials were in smallholder dairy farms Validation of ITM in Tanzania was between 1989-2002 in different regions, including Iringa, Mbeya, Dar es Salaam, Morogoro, Kagera, Mwanza, Arusha, Kilimanjaro, Tanga Shinyanaga, Mtwara, Lindi and Kigoma districts. Initially trials were conducted in smallholder dairy (90%) and commercial dairy (10%) but later shifted to indigenous pastoral systems 90%. Who are the Users? ITM is being delivered commercially by private veterinarians in Narok, Kajiado and Mara districts of Kenya. The private vets were initially supported to set up ITM delivery centres by VSF-Germany an international NGO. Pilot delivery by private veterinarians is also under way in medium to large scale dairy areas in Uasin Gishu districts and Laikipia districts in collaboration with the KARI and ILRI. Vetagro-Tanzania took over delivery of ITM in Coastal areas of Northern Tanzania from ITTBD project. Currently there is also a FAO funded delivery by public sector through the Ministry of Water and Livestock Development other parts of the country In Uganda and Zambia ITM is currently delivered by the veterinary department. The government is responsible to sources and delivering although private vets can deliver but with approval by the government Where the outputs have been used: ITM is currently being used in the following countries: Kenya-Narok and Kajiado (pastoral) Uasin Gishu (dairy) and Laikipia (large scale commercial) districts Tanzaina-Arusha region-pastoral, Tanga (smallholder dairy), Southern highlands (agropastoral) Uganda-Several districts targeting mostly smallholder dairy. Zambia- Eastern and Southern provinces of Zambia. Mostly in agropastoral production systems. Scale of Current Use: The scale of current use can only be described as modest. Zambia has the largest number of users followed by Tanzania, and Kenya. Zambia currently uses about 50,000 doses per year making a total of about 300,000 cattle immused since ths start of the programme. Tanzania is currently using 30,000 doses and has far immused about 200,00 cattle. Kenya is currently using about 5,000 doses per year and in the last two years since the start fo commercial delivery a total 10,00 cattle have ben immunised. The numbers of cattle currently immunised in Malawi and Uganda is estimated to be low limited due various factors including lack of promotion and commercialisation of distribution/ delivery. Although there is considerable demand and use is spreading, it is hampered by a number of factors such government restrictions, vaccine supply and service delivery. A lack of full involvement of the private sector is also a factor. It is estimated that at moderate adoption rates 10-30% a total of 1.5million doses of an ECF vaccine could be used in the region. Policy and Institutional Structures, and Key Components for Success: The various donor funded programmes in the region have helped in the refining of the technology to the point where it is now acceptable to all stakeholders as a safe product. ILRI technical expertise in ECF and vaccine stabilates production has played a critical in creating the necessary confidence by allaying fears due to an inadequate understanding of the epidemiology of the disease . The support by DFID to develop molecular tools for parasite characterisation and the use of these tools in the FAO supported production of the last vaccine batch which is in current use was pivotal. The presence in the regional of strong NARS (KARI in Kenya, LIRI in Uganda and ITTBD in Tanzania) with well trained technical staff was also crucial in the promotion of the technology. Use of the technology has also been assisted by the failure of previous control methods principally tick control. Due to reduced government funding in animal health subsidies in tick control have been withdrawn resulting in an inefficient tick control programmes. The development of resistance by ticks to various acaricides has worsened the problem. Lessons Learned and Uptake Pathways Promotion of Outputs: In Kenya promotion of ITM is taking place in the Maasai pastoral system (Narok, Kajiado and Mara districts) in Kenya. Promotion is also taking place in the dairy areas and to lesser extent in the large scale commercial beef production areas. In Tanzania the technology is being promoted in most parts of the country through an FAO project. Vetagro Tanzania is also promoting the technology in the Arusha region of the northern parts of the country. The current promotion has supported immunisation of more than 80,000 cattle in 2006 and this number could rise to above 100,000 during this year. Potential Barriers Preventing Adoption of Outputs: There are several barriers which are preventing and slowing the pace of adoption of ITM in the region · There is currently no entity to sustainably produce a safe reliable vaccine. ILRI produced the last batch with funds provided by FAO. It believed only the private sector can play this role in sustainable way. · Private sector has been reluctant to invest in production until clear policies are in place. The ambivalence of some governments about the role of the private sector has slowed the adoption of the technology. · Lack of a harmonised regional commercialisation to take advantage of the larger market has also inhibited adoption of the technology. · Continued concerns by some stakeholders on about safety, issues related to carrier states in cattle, parasite recombination have slowed adoption. · Technical issue such as the number of doses in bottle has bee a constraint to adoption because of low number of cattle per household and the requirement to use the vaccine within a given period after reconstitution. · The fact that the use of the ITM leads to reduction in the use of the some conflicts with existing products such as acaricides and curative drugs have made some service providers reluctant to promote the technology How to Overcome Barriers to Adoption of Outputs: · A public-private partnership may be required, at least initially, to establish an effective production centre. The start-up costs to establish appropriate facilities, technologies and expertise are high and the private sector may be unwilling to invest in this process. · Since the market s are fragmented by national borders and production system, a harmonised regional approach to ITM would help the technology greatly. · A clear policy on the role of the private sector in the distribution of ITM would allow the sector to be fully involved in the technology. · Studies to identify the impact of technology in terms of social effects would allay fears from service providers on the likely loss of business and help then promote the technology Lessons Learned: · Appropriate government policies have been critical without which little progress can be made. · Well documents science based evidence would influence decision making by policy makers · All the concerns of all the stakeholders must be addressed. Identifying the stakeholders and involving them at the appropriate stage is very critical. · Institutional interests must be addressed even though quite often they might be working against national interest can be quite a problem. A suitable mechanism to either accommodate them or deal with their consequences must be sought. Poverty Impact Studies: · Katherine Homewood , Pippa Trench, Sara Randall Godelieve Lynen , Beth Bishop. 2006. Livestock health and socio-economic impacts of a veterinary intervention in Maasailand: Infection-and-treatment vaccine against East Coast fever. Agricultural systems 89 248-271. · KM Homewood, Anthropology, University College, London; k.homewood@ucl.ac.uk. Pastoral disease risk management Household and focus group studies of livelihoods and pastoral risk management. Technical report · Emong'or, R.A., Kiara, H., Randolph, T. F., Okuthe, O.S., Leneman, J.M. and Wanyangu, S.W. 2002. KARI/ILRI Collaborative Study of Improved Control of East Coast Fever in Smallholder Dairy Production Systems. Technical report · Emongor, R.A., Kiara, H. Randolph, T. F., Okuthe, O.S. Leneman, J.M. and Wanyangu, S.W. 2000. Ex-post impact assessment of the ITM technology for control of East Coast fever (ECF) in Kenya. Technical report · A rapid appraisal study of the delivery of the infection &treatment method for east coast fever immunization in Uganda, 2003. A report of by the task force on ECF-ITM impact assessment MUK/MAAIF/NARO/ILRI, funded by the International Fund for Agricultural Development (IFAD). Technical report. · Deployment of a live vaccine in pastoral areas: lessons learned from Tanzania. G.Lynen , G.Di Giulio, K.Homewood , Robin Reid, Angello Mwilawa. Paper presented at the Fourth All Africa Conference on Animal Agriculture, Arusha, Tanzania, Sept. 2005 Direct and Indirect Environmental Benefits: Environmental impacts of the use of vaccines for ECF control compared with the more conventional use of acaricides have been reviewed. The major direct environmental impact of widespread vaccine use will be positive with a reduction in the production, use and disposal of these toxic chemicals. Indirect effects on cattle populations in different production systems are less easy to predict. Reduced mortality risk in young stock will allow livestock keepers more choices and income opportunities but could result in overstocking in some circumstances. However, with significant reductions in calf mortality overstocking to counteract losses due to ECF could be kept to a minimum. Introduction of improved cattle breeds is made possible as demonstrated in northern Tanzania. This could permit greater output of milk and meat from fewer cattle, with a consequential reduction of environmental effects. Formal bio-safety procedures for assessing the potential environmental impact of deployment of a recombinant vaccine will be conducted prior to and during field trials through the Kenya National Bio-safety Committee. Merial PLC has a number of commercial vaccines deployed worldwide that use the canary and fowl pox virus delivery systems being evaluated for ECF. Adverse Environmental Impacts: Input required? - There has been a fear that with increased survival of ITM-immunised calves there would be greater environmental impact of larger numbers of calves being reared. The Tanzanian study indicates that increased calf numbers are counter-balanced by increased take-off of healthier young stock. Coping with the Effects of Climate Change, or Risk from Natural Disasters: Input required? - The increased income of poor farmers as a result of ITM permits them to invest in materials and goods that will give them some resilience to natural disasters and climate changes. The study in northern Tanzania indicates that ITM immunised cattle are healthier and put on weight more quickly this will increase the resistance of these cattle to external stresses. As a consequence, poor people will also be able to cope more effectively with these external stresses. Relevant Research Projects,
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For relevant research projects, with links to further information
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