Launching of the first recombinant vaccine against Hydatidosis in Argentina. Development of a new tool to protect intermediate hosts

THELMA VERONICA POGGIO; LIGHTOWLERS MARSHALL; HEATH DAVID ; JENSEN OSCAR; LA TORRE JOSE1

Buenoa Aires

Congreso; 23rd International Conference of the World Association for the Advancement of Veterinary Parasitology; 2011

the World Association for the Advancement of Veterinary Parasitology

Launching of the first recombinant vaccine against Hydatidosis in Argentina Development of a new tool to protect intermediate hosts Poggio Thelma 1, Jensen Oscar2, Lightowlers Marshall 3, Heath David 4, La Torre Jose1 1. Centro de Virología Animal ? CEVAN-ICT Milstein (CONICET) 2. Departamento Zoonosis - Secretaría de Salud (Chubut). 3.Molecular Parasitology Laboratory, The University of Melbourne, Australia 4. AgResearch, Wallaceville Animal Research, New Zealand Echinococcosis by Echinococcus granulosus is a worldwide zoonotic disease whose epidemiology and control is often considered to be a veterinary matter. Therefore, a recombinant vaccine has been developed for prevention of infection of the intermediate hosts by Heath & Ligthtowlers in 1995. CEVAN-ICT Milstein belonging to CONICET, together with the University of Melbourne and AG Research made possible to produce a pilot scale vaccine that utilizes the recombinant oncosphere protein, EG95. In February 2011 Providean Hidatil EG95®, was approved by Argentina´s Animal and Plant and Food Safety Agency (SENASA) as the first recombinant vaccine for use in sheep and goat. Tecnovax S.A. obtained the registration certificate for the new product and carried out the scaling up and production. The efficacy of Providean Hidatil EG95® was compared with the recombinant Australian vaccine and the bioequivalence was demonstrated. Methods EG95 gene was cloned from mRNA Echinococcus granulosus eggs of the tapeworm parasite of dogs. The semi-purified recombinant EG95-GST protein expressed in bacteria was combined with Montanide ISA 70 plus saponin as emulsifying agent. Three groups of sheep (n=10) were immunized subcutaneously on days 0, 30 and 365 with different formulations. Group 1 was immunized with Providean Hidatil EG95® (50µg/dose). Group 2 received the Australian formulation (50µg Eg95-GST plus 1 mg QuilA). Control sheep received no antigen. Efficacy of Providean Hidatil EG95® was proved by monitoring the serological response of sheep in comparison with sera from sheep immunized with the Australian formulation. Results and Conclusions Providean Hidatil EG95® induced high titers of specific IgG antibodies in sera from immunized sheep that persist for more than one year and did not show significant differences with those induced by the Australian vaccine. This trial demonstrates that Providean Hidatil EG95® is bioequivalent to the Australian formulation. The production of the first licensed recombinant veterinary vaccine is a prominent fact in our country. The inclusion of this practical tool in the program for controlling hydatidosis will allow to prevent the illness in the intermediary hosts through elicited seroprotection and the subsequent reduction of the offering hydatid cysts.