Feasibility and Challenges of Embryonated Chicken Eggs as Alternative Models for Mammalian Experimental Animals

Chun-Yi Chiang

Abstract

Under the global emphasis on laboratory animal welfare and the 3Rs (Replacement, Reduction, and Refinement) principles, the development of non-mammalian alternative models with both biological relevance and experimental feasibility has become a critical issue in biomedical research. Owing to its short developmental cycle, high cost-effectiveness, ease of manipulation, and relatively low infrastructure requirements, the embryonated chicken egg model has gradually emerged as an important intermediary platform bridging in vitro cell-based screening and mammalian animal validation studies. During embryonic development, the chorioallantoic membrane exhibits a highly vascularized structure, making it a valuable platform for studies of angiogenesis and pharmacokinetics. In addition, the immature immune system of early-stage chicken embryos reduces xenograft rejection responses, thereby significantly improving the success rate of tumor cell xenotransplantation. Currently, this model has been widely applied in multiple research fields, including drug toxicology and teratogenicity assessment, oncology research, biomaterial biocompatibility testing, pathogen isolation and cultivation, and vaccine development. Despite these advantages, several limitations remain, including interspecies differences between avian and mammalian systems, the relatively restricted experimental observation window, and potential animal welfare and ethical concerns associated with nociception during later stages of embryonic development. Future studies integrating gene-editing technologies for disease model establishment, together with advanced imaging techniques and artificial intelligence-based analyses, are expected to improve the stability and reproducibility of the model and further expand its applications in both translational medicine and precision medicine.

Field trial of inactivated porcine epidemic diarrhea vaccine

Yu-Liang Huang

Abstract

Porcine epidemic diarrhea virus (PEDV) is one causative agent of diarrhea in piglets in Taiwan and led to high mortality in suckling pigs. In order to reduce the economic losses caused by this disease, an inactivated PEDV vaccine was developed. This vaccine is formulated using a novel attenuated PEDV strain combined with an adjuvant. Field trials demonstrated that the vaccine is highly safe for pregnant sows. Following intramuscular vaccination, sows develop high levels of PEDV-specific antibodies in colostrum. These maternal antibodies are transferred to piglets through colostrum intake, resulting in elevated PEDV antibody levels in neonatal piglets. Consequently, the vaccine effectively decreased mortality and clinical symptoms in suckling piglets, thereby improving piglet survival and overall production performance.