Transgenic Eimeria parasite: A potential control strategy for chicken coccidiosis

•Eimeria immunodominant antigens are valuable asset for novel anticoccidial vaccines design.•Transgenic Eimeria is currently used as delivery vehicle of vaccine antigens.•Stable transfection protocols are instrumental to the construct of transgenic Eimeria. Poultry industry has been very instrumental in curtailing malnutrition and poverty and as such contributing to economic growth. However, production loss in poultry industry due to parasitic disease such as coccidiosis has become a global challenge. Chicken coccidiosis is an enteric disease that is associated with morbidity and mortality. The control of this parasite through anticoccidial live vaccines and drugs has been very successful though with some limitations such as the cost of production of live vaccines, and drugs resistance which is a public health concern. The discovery of Eimeria vaccine antigens such as Apical membrane antigens (AMA)-1 and Immune mapped protein (IMP)-1 have introduced the use of recombinant vaccines as alternative control measures against chicken coccidiosis. Although some protections have been reported among recombinant vaccines, improving their protective efficacy has triggered the search for a novel and efficient delivery vehicle. Transgenic Eimeria, which is constructed either through stable or transient transfection is currently being explored as novel delivery vehicle of Eimeria vaccine antigens. Due to partial protections reported in chickens vaccinated with transgenic Eimeria lines expressing different Eimeria antigens, improving protective efficacy becomes imperative. Recent trends in the design of transgenic Eimeria for potential application in the control of chicken coccidiosis are summarized in this review. We conclude that, with improved protective efficacy using multiple vaccine antigens, transgenic Eimeria parasite could fill the gap in the control of chicken coccidiosis as an efficient anticoccidial vaccine.