One year old baby with chickenpox vaccine may have localized slight redness, swelling and pain, slight fever, slight rash and other reactions. 1. localized slight redness, swelling and pain: one year old baby after vaccination, due to the stimulation of drugs, can lead to vaccination site can appear slight redness, swelling, pain reaction, most of the 2 ~ 3 days after the natural disappearance. 2. Slight fever: as a one-year-old baby chickenpox vaccine, can trigger the corresponding immune response, may lead to the baby appeared slight fever symptoms. This fever is usually transient and does not last long. 3. Slight rash: Due to individual differences, a small number of one-year-old babies can have an allergic reaction with a mild rash after chickenpox vaccination. When one-year-old babies need to take chickenpox vaccine, it is recommended to consult a professional doctor and take the injection under the guidance of the professional doctor.