Congenital Toxoplasmosis: Prevention of Vertical Disease Transmission by Vaccination

Abstract

The efficacies of four different types of microwaved Toxoplasma gondii vaccines were evaluated for their ability to elicit protection in Swiss strain pregnant mice and their pups. Protection of dams and their pups was evaluated by parasitological and pathological studies. Mice were divided into 4 groups. Preimmunization of pregnant mice was done before mating. The first group immunized with tachyzoite vaccine alone, the second with tachyzoite vaccine in combination with cytokine IL_-12, the third with microwaved cyst vaccine alone and the fourth group with microwaved cyst vaccine combined with cholera toxin. All groups were challenged with the virulent RH- strain of Toxoplasma gondii between the 10^th and 14^th day of gestation. The results showed highest level of protection in dams vaccinated with cyst vaccine in combination with cholera toxin followed by vaccine group in association with the cytokine IL12. The combination of the vaccines with the adjuvant strengthened the vaccine effect, thus documented by the improvement of histopathological changes in the organs of both dams and pups compared to the infected control group organs. The study proposes the implication of this vaccineagainst the infection with Toxoplasma gonidii, not only in mice, but also in other mammalian hosts including women.