Novel CRISPR-Based Vaccine Shows Protection Against Marek’s Disease

Scientists from Henan University of Science and Technology and partners have developed a novel vaccine using CRISPR-Cas9-based gene editing to target hypervirulent Marek's disease virus (MDV), a major cause of economic losses in the poultry industry. The findings of the study, published in Poultry Science, highlight the growing challenge of emerging MDV strains that evade protection from existing commercial vaccines.

The research team developed a double-gene deleted vaccine that targets both the oncogene meq and LAT-clustered microRNAs, which are linked to tumor formation and viral persistence. Comprehensive experiments confirmed the gene deletions, genetic stability, and replication, without affecting the expression of essential viral genes. The researchers reported that further animal tests showed no histopathological lesions or neoplastic changes, demonstrating the vaccine's strong safety profile in chickens.

Trials revealed that the novel vaccine achieved a protection index of 88.9% against a hypervirulent MDV strain, surpassing the 70.6% protection offered by the standard CVI988 vaccine. These findings offer a promising strategy for developing highly efficient vaccines against Marek's disease and other herpesviruses.

For more information, read the study from Poultry Science.