Toxoplasmosis caused by Toxoplasma gondii is a global zoonosis threat. This parasite has two final hosts (cats) and intermediate hosts (a wide range of warm-blooded animals).The most important complication of the parasite is abortion in pregnant women and domestic animals such as sheep and pigs, although in people with a weak immune system, the disease occurs in the form of lung inflammation (pneumonia) or brain (encephalitis). The parasite has three pathogenic forms for humans, each of which plays a major role in epidemiology and disease transmission: oocyst (contaminated water and food), tachyzoite (congenital or blood-borne transmission) and bradyzoite (transmission through organ donation or meat products). infected with tissue cysts).

More than 30 years have passed since Toxoplasma vaccination studies, but the commercial vaccine for humans has not yet reached the production stage. Killed or attenuated vaccines are not of much interest today in terms of safety issues for humans or immunogenicity in the body, but on the other hand, subunit vaccines are of interest to researchers. From this category of vaccines, we can mention DNA vaccines or protein vaccines, which often together with an adjuvant or helper are able to produce a suitable immune response against the parasite. In this way, many antigens from different life stages of the parasite have been identified and investigated to evaluate their immunogenicity, including surface antigens (SAGs), and organelle antigens in tachyzoites and bradyzoites such as microneme (MIC) , Roptery (ROP) and dense granules (GRA). During the last few decades, bioinformatics tools have greatly helped to identify vaccine candidate antigenic proteins or their immunogenic epitopes. The purpose of the present study is to design and computer evaluate a new vaccine candidate against Toxoplasma gondii using an immunogenic epitope derived from several surface antigens related to SAG1 or SRS proteins expressed in the tachyzoite stage of the parasite.