Veterinary Parasitology 113 (2003) 135–144 Failure of a recombinant Schistosoma bovis-derived glutathione S-transferase to protect cattle against experimental Fasciola hepatica infection J. De Bont a , E. Claerebout b , G. Riveau a , A.M. Schacht a , K. Smets b , G. Conder c , D.A. Brake c , A. Capron a , J. Vercruysse b,∗ a Inserm U547, Institut Pasteur de Lille, Rue du Prof Calmette, Lille 59019, France b Laboratory of Parasitology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium c Veterinary Medicine Research and Development, Pfizer Animal Health Group, Pfizer Inc., Eastern Point Road, Groton, CT 06340, USA Received 9 August 2002; received in revised form 9 December 2002; accepted 9 December 2002 Abstract The potential of a recombinant Schistosoma bovis 28-kDa glutathione S-transferase (rSb28GST) to protect cattle against Fasciola hepatica was tested in a vaccination trial. Thirty two calves were randomly divided into four groups of eight animals. Calves of the three vaccine groups received two intramuscular injections at 3 weeks interval, of 0.250 mg rSb28GST in either aluminium hydroxide (Al(OH) 3 ), Quil A, or PBS emulsified in an equal volume of Freund’s complete adjuvant (FCA). Animals of the control group received injections of Al(OH) 3 /PBS only. All animals were chal- lenged orally with a total of 360 metacercariae of F. hepatica, spread over 6 weeks. All groups of vaccinated animals produced measurable IgG antibody titers to rSb28GST after vaccination. Animals immunised with FCA adjuvanted vaccine had the highest and more durable antibody titers and only sera from this group recognised an approximately 24 kDa protein band from F. hepatica, that is thought to be a F. hepatica GST. Despite a good antibody response differences in cumulative faecal egg output between the groups were not statistically significant. In addition, no significant difference was found between groups in terms of total worm numbers or percentage of immature flukes recovered at necropsy. In conclusion, the recombinant S. bovis 28 kDa GST was not found to adequately protect cattle against experimental F. hepatica challenge, using either aluminium hydroxide, Quil A or FCA as adjuvant. © 2003 Elsevier Science B.V. All rights reserved. Keywords: Fasciola hepatica; Cattle-trematoda; Vaccine; Glutathione S-transferase ∗ Corresponding author. Tel.: +32-9-264-7390; fax: +32-9-264-7496. E-mail address: jozef.vercruysse@rug.ac.be (J. Vercruysse). 0304-4017/03/$ – see front matter © 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0304-4017(02)00450-8