We evaluated the usefulness of the combination of three plasmids
encoding tegumental (pECL and pSM14) and muscular (pIRV5) antigens of the
Schistosoma mansoni
on improving the protective immunity over the use of a single antigen as
DNA vaccines. Female BALB/c mice were inoculated twice with 25 µg DNA
plasmid within two weeks interval. The challenge was performed with 80 cercarias
of a regional isolate of
S. mansoni
(SLM) one week after the last immunization. Six weeks after challenge, all
mice were perfused for worm load determination. The following groups were
analyzed: saline; empty vector; monovalent formulations of pECL; pSM14 and
pIRV5 and also double combinations of pECL/pIRV5 and pIRV5/pSM14 and a triple
combination of pECL/pIRV5/pSM14. The protection was expressed as a percentage
of worm loads in each group compared with the saline group. The results
obtained were 41% (p < 0.05); 52% (p < 0.05); 51% (p < 0.05); 48%
(p < 0.05); 55% (p < 0.05); 45% (p < 0.05); 65% (p < 0.05) for
each group respectively.
