Infants crying after the second injection of hepatitis B may be caused by pain due to injection, adverse drug reactions, etc., and need to be relieved through soothing, give the baby more water and other methods. 1. Pain caused by injection: During the process of injecting the second vaccine for hepatitis B, it may be due to the excessive strength of the injection and other reasons, resulting in the baby’s pain and causing crying. In this case, you need to calm the baby in time and divert the baby’s attention, and usually the crying will disappear gradually. 2. Adverse drug reactions: after the second injection of hepatitis B, some infants may experience vomiting, diarrhea, local redness, swelling, pain and other adverse reactions, which make infants feel uncomfortable and cause crying. In this case, you need to give your baby more water to accelerate the body’s metabolism, and usually the symptoms will be gradually relieved. At the same time, you need to pay more attention to observe the state of the baby. If the infant’s crying is not relieved for a long time after the second injection of Hepatitis B, it is necessary to go to the hospital in time for relevant examination and treatment.