Dr. Sajid Ur Rahman is a researcher specialising in infectious diseases, host–pathogen interactions and gut microbiota. He earned his Ph.D. from the Chinese Academy of Agricultural Sciences and completed postdoctoral training at Shanghai Jiao Tong University. He is currently affiliated with the School of Medicine at Southern University of Science and Technology. His research focuses on Hepatitis Delta Virus (HDV), particularly genotype-specific regulation, RNA structural checkpoints, and functional mutations in HDAg. He has secured competitive funding, published peer-reviewed articles, and established international collaborations to advance molecular virology and translational infectious disease research.