The reasons why babies don’t sleep after vaccination and how to deal with them include: 1. fear psychology, many babies will have fear psychology when they are vaccinated, and they can’t get over it for a long time after vaccination, so they need parents to coax and hug them, and give them enough security to make them forget their fear, so that they can sleep normally as usual. 2. pain, many vaccines are subcutaneous intramuscular injections which are painful, and some vaccines will have redness, swelling, heat and pain after injection, so it will affect their sleep. After the injection, some vaccines will show redness, swelling, heat and pain, which will make the baby uncomfortable and affect the sleep. 3. Parents must pay attention to observe and be alert to the occurrence of serious allergic reactions, and need to bring the baby to the hospital for examination in time.