Evaluation of experimental Toxoplasma gondii vaccine in cats

Toxoplasma gondii is an intracellular parasite with a wide range of host species. As the final host, the cats play an important role in the environment contamination and other hosts infection. Therefore, preventing the shedding of Toxoplasma oocysts in cats play a significant role in controlling the disease. The purpose of this study is to evaluate the live attenuated strain of toxoplasma gondii experimental vaccine that was prepared at the Razi Institute in order to prevent the shedding of oocysts by cats. In this study, ten native male cats were randomly divided into two equal groups. The first group received the attenuated strain and the second group received the culture medium as a control. Immunization conducted twice (3 week interval) by subcutaneous injection. Clinical symptoms were observed and recorded daily from the beginning of the experiment until one month after the second injection. One month after the second injection, all cats were challenged orally with the PRU strain. The agglutination serological test and the molecular test results showed a significant immune response and protective immunity in the vaccinated group compared to the control group (p<0.05). In general, the evaluation of the attenuated strain on cats as an experimental vaccine showed that this vaccine, in addition to creating an immune response and controlling oocyst shedding, did not cause any specific pathogenicity in the vaccinated group. Therefore, it is suggested to carry out additional research on this experimental vaccine in a long time with a larger number of cats.