A project entitled Peste des petits ruminants (PPR): homologous vaccine
trial. Biochemical analysis of the virus and specific diagnosis development
lead by Dr. A. Diallo of CIRAD-IEMVT in partnership with other scientific
institutions in France, Belgium, the Ivory Coast and Mauritania, was carried
out under the European Union (D.G.XII) STD2 scientific programme.
The Peste des petits ruminants (PPR) is a highly contagious viral disease of
goats and sheep, and it has increasingly significant economic impact on many
countries of Africa, Arabian Peninsula an Middle East.
The virus responsible for the disease shares many characteristics with the
rinderpest virus (RPV) which causes another important disease in small
ruminants and in cattle.
For this reason, differential diagnosis of both diseases is not easily done by
conventional methods. Moreover traditional vaccination against PPR using PPV
vaccines, complicates the diagnosis and consequently the control and
eradication programs of both diseases.
In this project, dr Diallo and his collaborators have developed three main
areas of important research on PPR:
-Field trials of a specific vaccine, previously obtained by authors, using a
PPR virus attenuated by serial passages in cell cultures;
-Biochemical analysis of the PPR virus and
-Development of new diagnostic methods.
Besides the in vivo experimental studies, the PPR homologous vaccine has been
tested in more than 20 000 small ruminants in the Ivory Coast. High percentage
(>85 % animals) of vaccinated animals developed strong immune responses and
they survived a natural outbreak of the disease. In experimental conditions
the vaccine has shown to induce passive protection of newborns during the
first 10-15 weeks of life and vaccinated animals have shown fully protected
against infection and transmission of rinderpest virus.
The analysis of the PPR virus genetic material using recent procedures of
molecular genetics has Clearly shown its composition in comparison with virus
of the same group namely the RPV.
The polymerize chain reaction (PCR), a novel technique which enables the
diagnosis of several diseases by identification of very small amounts of
genetic material has been also developed to detect PPR.
Other important diagnostic tools have also been obtained to improve the
diagnostic of the disease:
PPR-specific proteins were produced in large scale using very sophisticated
methods of genetic engineering, by means of manipulating other virus (bacula
virus) which can express foreign material during their replication. Such
proteins and newly obtained monoclonal antibodies specific for particular
viral components, have been used to improve the PPR detection by several
diagnostic procedures name, ELISA, agglutination and immunocapture.
Overall, the work developed by dr Diallo and his collaborators, within this
project is a major scientific contribution for the study of PPR, opening new
avenues on the establishment of prophylactic and diagnostic procedures towards
the control and eradication of the disease which has increasingly significant
economic and social impact on many developing countries.
Within this project several publications have been issued.
Contract number A-178
For further information please contact:
Dr. A. Diallo
10, Rue Pierre Curie
94704 Maisons- Alfort Cedex, France