Abstract: Abstract: 【Objective】To construct DNA vaccines for Haemonchus contortus (H. contortus), and test the protective effects in goats. 【Method】Three gene fragments encoding parts of H. contortus H11, named as H11-1, H11-2 and H11-3, were insert into pcDNA4/His Max C, respectively. And the recombinants were identified by double restriction enzyme digestion and sequence analysis. Lambs were immunized with DNA vaccines about 28 and 14 days before challenged by 10000 H. contortus L3. The expressions of vaccines in goat were tested by RT-PCR and Western blotting. And the IgG stimulated by the vaccines were checked by ELISA. After challenged with L3, EPG (eggs per gram feces), L3 hatched from eggs and worm burdens of lambs were counted, respectively. 【Result】 Transcriptions and translations of the vaccines in goat muscles were conformed at 7 days post primary immunization and 1 week after boosting. And the serum anti-H11 antibodies could be inspected by ELISA about 10 days after first immunization. After challenged with L3, it was found that EPG, percents of L3 hatched from eggs and worm burdens of lambs, immunized with H11 DNA vaccines were reduced 58.75%, 72.57% and 68.25% respectively, compared with the goats administered with pcDNA4/His Max C. 【Conclusion】 The results showed us that the recombinant plasmids carry H11 gene could protect lambs from the infection of H. contortus effectively.

Key words: goat, Haemonchus contortus, H11, DNA Vaccine