Iodophor is a common disinfectant that may cause BCG vaccine to be ineffective or less effective. BCG is a live mycobacterial vaccine made using a suspension of attenuated bovine mycobacterium tuberculosis, which enhances the activity of macrophages and thus their ability to phagocytose pathogens, providing prevention of tuberculosis, in addition to adjuvant treatment of tumors. BCG vaccine injection may be pus, followed by breakage and scabbing, because BCG is a live bacterial vaccine, and iodophor can kill bacteria, fungi, etc., so the use of povidone-iodine after BCG pus may kill the relevant live bacteria, resulting in BCG vaccine failure or reduced effectiveness. The use of povidone-iodine to rub the BCG vaccine after it has become pus-filled may cause the BCG vaccine to become ineffective or less effective, and it is recommended that the pus be handled promptly under the guidance of a doctor.