Final Report Summary - RP/PPR MARKVAC (Development of marker vaccines, companion diagnostic tests and improvement of epidemiological knowledge to facilitate control of rinderpest ...)
The main objectives of the RP/PPR MARKVAC project were the following:
Task I: Development of marker vaccines for Rinderpest (RP) and Peste des petits ruminants (PPR)
- To develop marker vaccines capable of preventing RP and PPR infections. These vaccines would be able to differentiate between infected and vaccinated animals using the available antibody detection tests. The production of marker vaccines for RP and PPR is possible using reverse genetics technology.
- To develop companion tests to differentiate between infected and vaccinated animals. Through the use of these tests the continuation of serosurveillance to detect foci of the disease was possible while vaccinating. This would allow for a quicker lifting of control measures.
- To improve and investigate the quality and the safety of the marker vaccines. This would be made by means of the reverse genetics technology from the vaccines derived from the current attenuated strains. The potential for environmental spread of Genetically modified organisms (GMO) used as vaccines, would be investigated, characterised and compared with the parental non-modified strains.
- Improvement of the vaccine thermal stability and delivery to animal. Quality of the new generation vaccines in terms of biological activity and stability were important issues that had to be addressed. Improved formulations for storage of vaccines at higher temperatures may accelerate the development of new immunisation technologies, such as lyophilised powder and nanoencapsulated materials for mucosal delivery.
Task II: Diagnostic test development
- Improve and validate diagnostic tests on their sensitivity and specificity. Newly developed ELISAs based on the detection of antibodies to vaccine markers (positive and negative markers) would be compared with the existing serological tests to identify antibodies to these viruses. These tests would broaden the understanding of the epidemiology of RP in the remaining infected areas and of the epidemiology of PPR.
Task III: Improvement of information systems for PPR surveillance and decision making
-To conduct spatial description and analysis of PPR. This study would produce whole country maps of the frequency of PPR based on information already available from previous surveys and information that may become available as a result of the project. Risk models and monitoring tools would be generated which would be used for early warning, surveillance, and decision support for intervention.
- To develop models of disease transmission. Network structure of the population of susceptible species at the local level would be defined to obtain estimates of between - flock or between - areas transmission. To obtain within flock transmission parameters, experimental studies would be conducted. This information could be used to inform strategies for the surveillance and control of PPR in enzootic countries and additional support to some existing European Union (EU) developing country programmes.
- Part of MARKVACs innovation would be to combine spatial data (Earth observation data, geographical information systems) with epidemiological data.
In this project positively and negatively marker vaccines for RP and PPR viruses based on reverse genetics technology were developed. The positive impact of this research would be best seen in areas experiencing the diseases for focused ring vaccination to control or eradicate the disease, combined with appropriate companion tests that allow differentiation of vaccinated from infected animals. To determine the status of PPR in any area and take the appropriate action, apparent prevalence of PPR in the studied sites was estimated with current tests having validated performance characteristics. The compiled information was organised into a Geographical information system (GIS) which allowed the subsequent incorporation of information on new outbreaks. In addition, experimental studies were initiated to provide data and parameters for the disease transmission model. In association with the genetically marker vaccines, this could greatly help with the control measures for PPR in the enzootic areas.
Task I: Development of marker vaccines for Rinderpest (RP) and Peste des petits ruminants (PPR)
- To develop marker vaccines capable of preventing RP and PPR infections. These vaccines would be able to differentiate between infected and vaccinated animals using the available antibody detection tests. The production of marker vaccines for RP and PPR is possible using reverse genetics technology.
- To develop companion tests to differentiate between infected and vaccinated animals. Through the use of these tests the continuation of serosurveillance to detect foci of the disease was possible while vaccinating. This would allow for a quicker lifting of control measures.
- To improve and investigate the quality and the safety of the marker vaccines. This would be made by means of the reverse genetics technology from the vaccines derived from the current attenuated strains. The potential for environmental spread of Genetically modified organisms (GMO) used as vaccines, would be investigated, characterised and compared with the parental non-modified strains.
- Improvement of the vaccine thermal stability and delivery to animal. Quality of the new generation vaccines in terms of biological activity and stability were important issues that had to be addressed. Improved formulations for storage of vaccines at higher temperatures may accelerate the development of new immunisation technologies, such as lyophilised powder and nanoencapsulated materials for mucosal delivery.
Task II: Diagnostic test development
- Improve and validate diagnostic tests on their sensitivity and specificity. Newly developed ELISAs based on the detection of antibodies to vaccine markers (positive and negative markers) would be compared with the existing serological tests to identify antibodies to these viruses. These tests would broaden the understanding of the epidemiology of RP in the remaining infected areas and of the epidemiology of PPR.
Task III: Improvement of information systems for PPR surveillance and decision making
-To conduct spatial description and analysis of PPR. This study would produce whole country maps of the frequency of PPR based on information already available from previous surveys and information that may become available as a result of the project. Risk models and monitoring tools would be generated which would be used for early warning, surveillance, and decision support for intervention.
- To develop models of disease transmission. Network structure of the population of susceptible species at the local level would be defined to obtain estimates of between - flock or between - areas transmission. To obtain within flock transmission parameters, experimental studies would be conducted. This information could be used to inform strategies for the surveillance and control of PPR in enzootic countries and additional support to some existing European Union (EU) developing country programmes.
- Part of MARKVACs innovation would be to combine spatial data (Earth observation data, geographical information systems) with epidemiological data.
In this project positively and negatively marker vaccines for RP and PPR viruses based on reverse genetics technology were developed. The positive impact of this research would be best seen in areas experiencing the diseases for focused ring vaccination to control or eradicate the disease, combined with appropriate companion tests that allow differentiation of vaccinated from infected animals. To determine the status of PPR in any area and take the appropriate action, apparent prevalence of PPR in the studied sites was estimated with current tests having validated performance characteristics. The compiled information was organised into a Geographical information system (GIS) which allowed the subsequent incorporation of information on new outbreaks. In addition, experimental studies were initiated to provide data and parameters for the disease transmission model. In association with the genetically marker vaccines, this could greatly help with the control measures for PPR in the enzootic areas.