ANTI-FECUNDITY IMMUNITY TO SCHISTOSOMA-JAPONICUM INDUCED IN CHINESE WATER-BUFFALOS (BOS-BUFFELUS) AFTER VACCINATION WITH RECOMBINANT 26-KDAGLUTATHIONE-S-TRANSFERASE (RESJC26GST)

We have shown previously that immunisation of mice and pigs with recom binant 26 kDa GST (reSjc26GST) induces a pronounced anti-fecundity eff ect after experimental infection with Chinese Schistosoma japonicum. W e report here that anti-fecundity immunity can also be induced against reSjc26GST in Chinese water buffaloes (Bos buffelus), important reser voir hosts for S. japonicum in China. Anti-Sjc26GST antibodies were pr oduced in immunised buffaloes and, following challenge with S. japonic um cercariae, a 22.3% reduction in worm numbers was evident in vaccina ted when compared with control animals. The anti-fecundity effect was characterised by a significant decrease in faecal egg output and eggs deposited in host tissues with those in the liver and intestine being reduced by about 50%. In addition to the anti-fecundity effect, reSjc2 6GST reduced by nearly 40% the egg-hatching capacity of S. japonicum e ggs into viable miracidia. In terms of vaccination strategy, these eff ects would combine to diminish pathology in animals immunised with reS jc26GST and reduce transmission of schistosomiasis japonica.