Fever is an adverse reaction to vaccination. After the chickenpox vaccine, many babies can have fever, depending on the temperature, if the temperature is above 38.5 degrees and the child is not in good spirits, you can choose to reduce the fever with Merlin or Ibuprofen, and rub the body with warm water or drink more hot water, which can also help to reduce the temperature. If the fever is low, there is usually no need for special treatment, just rub with warm water and put on a fever-reducing patch. If it is more than that, it is not easy to go down with antipyretics or the temperature continues to be feverish for more than 3 days, it is best to go to the hospital to see.