If your baby develops a cold after vaccination, do not apply cold medication for the time being. Because vaccination is actually inoculation of a small amount of virus in the body, and most of the cold medicines are antiviral drugs, so if you give anti-cold medicines after vaccination, it will kill the vaccine, thus weakening the reactivity and protection of the vaccine. Many children will have runny nose or even mild fever after vaccination. These are general common reactions after vaccination and most of them can be relieved on their own after 1-2 days. If the symptoms of cold are more severe, and at the same time there is fever, body temperature > 38.5 ℃, and extremely depressed or poor mental health, you need to go to the hospital in time to see a doctor.