BCG is a live attenuated vaccine, and BCG has special properties. Most children will have pus after BCG injection, and it will heal soon after the pus is drained. If the abscess is broken during this period, do not worry too much, but use iodophor to help your child clean the broken wound 2-3 times a day and avoid getting wet until the wound is healed to avoid aggravating the infection. Usually, the wound will scab over and heal in a few days. If the child has fever during this period, the child can drink more warm water and carry out physical cooling if the temperature is below 38.5℃; if the temperature is over 39℃ or repeatedly, it is recommended to take the child to the hospital for medical examination and then treat the problem.