Usually, redness and swelling will appear about 2 weeks after BCG vaccination, and then pus, ulceration and scabbing will form after 8-12 weeks, which is a normal vaccination reaction. After BCG vaccination, if the baby is in good spirits, without persistent high fever or cough, parents do not need special treatment. If pustules and ulcers appear, there is no need to apply medicine or bandages, but the area should be kept clean and clothes should not be too tight. After the scab has formed, you need to wait for the scab to fall off naturally, do not pick the scab with your hands in advance. If the pus forms an ulcer and the lymph nodes in the armpit swell, it is recommended to go to a specialist hospital in a timely manner. In addition, try not to get water on the vaccination site after BCG vaccination to prevent infection.