Cross-protection validated initial Toxoplasma gondii proof of concept trial
1 August, 2016 - Pacific GeneTech (PGT) successfully completed a proof of concept trial against Toxoplasma gondii in mice. “This proof of concept study demonstrated that our recombinant vaccine including TRAP, MPP and HMGB1 and known to be effective in protecting chickens against Eimeria, could protect mammals against Toxoplasma infection”, Tim Collard, CEO of PGT said.
Results showed that after both oral and intra-peritoneal vaccination with PGT’s Eimeria vaccine, given as a low dose prime and boost, or as a single high-dose, mice showed up to 80% protection against the 100% mortality induced by Toxoplasma. This is the first example of a significant cross-protective effect with a PGT vaccine against two different genera of Apicomplexa. The vaccine has demonstrated efficacy against Eimeria in chickens and now 80% protection against Toxoplasma in mice. The vaccine was boosted by its Hercules adjuvant delivery system and then orally administered to mice.
Toxoplasma gondii is an apicomplexan protozoan parasite and a major public health problem, infecting one-third of the world’s population with other warm-blooded animals as its hosts. It infects a wide range of mammalian and bird species, and commonly infection leads to high economic burden (for example, abortion in sheep), also human impacts (such as congenital toxoplasmosis or neurotoxoplasmosis). With one exception (Toxovax, alive oocyst vaccine for sheep), there are no vaccines to prevent human or animal toxoplasmosis.
The study was conducted at the Graduate Institute of Animal Vaccine Technology at the National Pingtung University of Science and Technology (NPUST) in Taiwan.