A second dose of varicella vaccine is recommended for children. The varicella vaccine, as the only means of preventing the occurrence of chickenpox infection in children at present, not only prevents the occurrence of chickenpox, but also enables the prevention of complications caused by varicella zoster at the same time. The varicella vaccine, as a class II vaccine, can protect children at about 80% after the first dose, but if the second dose of varicella vaccine is administered, the protection rate for children can be about 95%, which will make the children more resistant to chickenpox and its complications, and greatly reduce the chances of developing the disease. It is recommended that the first dose be administered when the child is one year old and the second dose when the child is about four years old, and the specifics can be obtained from a medical professional.