Investigations of the antigenic differences between the EG95-G1 vaccine and related protein from the G6 genotype of Echinococcus granulosus (#86)
The EG95 vaccine is based on a recombinant protein
which native antigen is encoded by four genes in the G1 genotype of E.
granulosus. The EG95 vaccine has been successfully used under experimental
conditions raising protective immune response in intermediate hosts against the
challenge with E. granulosus from the same G1 genotype. No information
is available about the ability of the current EG95 vaccine to elicit a protective
immune response against other genotypes of E.
granulosus. Using genomic DNA cloning techniques, seven eg95–related
genes were characterised from the G6 genotype of E.
granulosus. Three proteins are predicted to be encoded by
these genes. Investigations were undertaken to determine the ability of two of
these proteins to react with specific antibodies in the sera of sheep
vaccinated with EG95 and shown to be protected against a challenge infection
with the G1 genotype. Proteins from the G6 genotype displayed only limited
antigenic cross-reactivity with the current EG95 vaccine antigen, suggesting
that the current vaccine may not protect animals against an infection with
parasites of the G6 genotype. Data presented provides the information that
would enable a G6 genotype-specific vaccine to be developed against E.
granulosus.