Very few people who have had chickenpox once can be infected again. Chickenpox is the pathogen is chickenpox – herpes zoster virus, the virus is only contagious to people, exists in the patient’s herpes blisters, blood and oral secretions, highly contagious. The source of chickenpox is mainly chickenpox patients, 1 to 2 days before the rash until the rash is dry and crusted, are infectious. In most cases, antibodies are produced in the body after a chickenpox infection and the person will not be infected again. However, varicella-zoster virus lurks in the nerve ganglia of the body for a long time, and when the body’s immunity is low, or when the body is tired, the virus is replicated in large quantities, and manifests itself as herpes zoster along the distribution of the nerves. As a reminder, chickenpox vaccination is the single most effective way to prevent chickenpox. Water vaccination is recommended for infants and young children of the appropriate age and for people with no history of chickenpox to prevent the development of chickenpox or shingles.