BCG and Hepatitis B vaccines are usually administered at the same time within 24 hours after birth, with one injection in the left and one in the right arm, and BCG does not necessarily specify which arm. BCG vaccine in 2-3 weeks after vaccination, will be localized small hard nodules, and then the hard nodules gradually soften, the formation of small pus or abscess, and then penetrate the skin to form shallow ulcers, and then scabs, when the scabs fall off can leave permanent scars. After BCG vaccination, it usually does not cause fever. Three months after BCG vaccination, a tuberculin test is performed. If the tuberculin test is positive, the vaccination has been successful; if it is negative, a new vaccination is needed.