Successful DNA immunisation of rats against fasciolosis

The liver fluke Fasciola hepatica contributes to great economic and health losses in the cattle industry in many countries, including Poland. Unfortun ately, no vaccine against fasciolosis is commercially available. We have de signed a DNA vaccine and tested it in rats. Groups of male or female rats r eceived one intramuscular injection of 50 mu g of a pcDNA 3.1 vector carryi ng cDNA encoding for a cysteine proteinase of F. hepatica. The plasmid was diluted in saline containing 0.05% bupivacaine. Control rats were injected with empty plasmid or not injected at all. All rats were challenged with 45 metacercariae of the fluke on day 28 of the experiment. Seven weeks after the challenge infection fluke burdens were evaluated in vaccinated and cont rol rats. Male rats vaccinated with cysteine proteinase cDNA revealed 100% protection against F. hepatica infection. Females immunised in the same way exhibited the reduction of fluke burden by 74%. (C) 2000 Elsevier Science Ltd. All rights reserved.