The tuberculosis vaccine, also called BCG, causes redness, swelling, and infiltration at the site of the vaccination two weeks after the BCG vaccination, which may be followed by pus and then ulceration, with crusting after 8-12 weeks. This condition does not require special treatment, but the area should be kept clean and dry to prevent infection. If the local abscess and ulcer are larger than 10 mm in diameter and have not healed for more than 12 weeks, prompt medical attention should be sought. BCG vaccine is injected at the lower edge of the deltoid muscle on the left upper arm, and the current domestic BCG vaccination procedure is once per person, mostly within 24 hours after birth, usually 0.1 mL per person. 4-8 weeks after vaccination, BCG vaccine will produce the corresponding antibodies, which can be maintained for 3-4 years.