Many mothers who do not understand the situation are worried when their babies develop pus and break down after BCG vaccination. However, this is actually a normal situation and there is no need to worry too much. On the contrary, if there is no redness, swelling, pus or breakage, you may really have to worry about the failure of vaccination. About 1-2 weeks after BCG vaccination, the baby will have small red local nodules, which will grow gradually and become slightly painful and itchy, but no fever; 6-8 weeks, pus blisters or ulcers will form; 10-12 weeks, scabs will start to form, and after the scabs fall off, a small, slightly red scar will be left, and later the red color will gradually turn into skin color. When there are localized pus blisters or ulcers after BCG vaccination, there is no need to rub or bandage them. However, the area should be kept clean, and clothes should not be worn too tightly. If there is pus flowing out, sterile gauze or cotton can be used to wipe it away, and do not squeeze it. Generally, local redness, swelling, infiltration, pus and small ulcers will appear around 2 weeks after BCG vaccination, and appropriate treatment should be taken for serious cases. If the local lymph nodes are swollen, hot compresses can be applied; if the pustules have softened and formed, sterilized syringes can be used to draw pus; if the pustules are perforated, 10% sulfonamide ointment or 20% para-aminoleucine ointment can be used. What are the precautions after vaccination for babies: 1. Observe for at least 15 minutes after vaccination to see if there is an allergic reaction, etc.; 2. Keep the vaccination site clean and cut the baby’s nails diligently so as not to accidentally scratch the injection site and cause infection, and also change the baby’s underwear diligently; 3. The broken area cannot be disinfected with alcohol, iodine, etc. so as not to affect the effect of the vaccine. If the breakout is serious, you can take your child to the hospital; 4. When bathing your baby, try to avoid getting water on the vaccination site, and if you accidentally get water on it, use clean gauze to absorb it as soon as possible; 5. If your baby has swollen lymph nodes less than 1cm and no abscess after BCG vaccination, you can apply hot compresses, preferably at a temperature of 40-45°C, so as not to burn your baby. The temperature of the hot compress is best at 40-45°C to avoid burning the baby, each time the hot compress lasts 10-15 minutes, and the hot compress can be applied 3-4 times a day. If there is an abscess, you must go to the hospital and not deal with it at home by yourself.