TNF and Mycoplasma pneumoniae pneumonia: The main limitation of this study is that the evaluation of the live vaccine (strain 168) was conducted solely on commercial Ningxiang pigs, a Chinese native pig breed, without assessing its efficacy in breeding herds of Ningxiang pigs and evaluating the cellular immune responses in porcine mycoplasmal pneumonia, including monitoring key indicators such as IFN-γ, IL-4, and TNF-α.