Does a Toxoplasma gondii EP67 conjugated epitope vaccine show efficacy in vivo?

Toxoplasma gondii (TG) is an obligate intracellular apicomplexan parasite. 30% of the world’s population is affected and it is the leading cause of birth defects in pregnant women and many livestock. Currently, there is no cure for the latent infection which has unknown implications in people. Therefore, it is imperative that a vaccine is generated to prevent bradyzoite cyst formation and blunt the spread of the parasite. To this end, we generated five 15-mer epitopes from TG genes known to be highly immunogenic. These were conjugated to a promising host-derived, molecular adjuvant EP67. Intraperitoneally (IP) immunized mice were observed and subsequently infected with 5,000 ME49 tachyzoites. For the duration of the trial the mice were weighed and monitored for signs of well-being. ELISA and qPCR assays were done to determine if the vaccine had prevented the latent stage infection