Pus in the area of the baby’s vaccination is usually a symptom of localized pus after the BCG vaccination in the left upper arm after birth. BCG vaccination is given 24 hours after the birth of a newborn baby to prevent tuberculosis, and is a mandatory vaccination for the national immunization program. There is no special local reaction after BCG vaccination. Generally, when the newborn is full-term, local redness and swelling will appear at the injection site and a lump will form, and some lumps will gradually become soft and form small pustules, which will break on their own and ooze yellowish-white pus, and then local ulcers and crusts will form, and then pus and crusts will flow again, repeatedly, and some children may go through such repeated times for 2 to 3 months, and finally The scar is a sign of successful BCG vaccination, so the redness, swelling, pus and scabbing at the site of BCG vaccination is a normal reaction to BCG vaccination. If the pus has broken down and flowed, we can use a clean cotton swab to gently wipe the pus and keep the area clean. So after BCG vaccination localized pus is a normal phenomenon, only need to do a good job of local cleaning, no need for special treatment.