WebMD explains the varicella, or chickenpox, vaccine -- why it's important, who should get it, the vaccine schedule, and possible side effects. Varivax Vaccine is administered by a healthcare professional and should not be self-administered. It protects the child from diseases that can be caused by the varicella virus. It is given to children between 12 months to 12 years of age and the second dose after a minimum gap of 3 months. Varicella (chickenpox) is an acute, highly contagious disease caused by varicella-zoster virus (VZV), a member of the herpesvirus family. Only one serotype of VZV is known, and humans are the only reservoir. Varicella vaccine, also known as chickenpox vaccine, is a vaccine that protects against chickenpox. [9] One dose of vaccine prevents 95% of moderate disease and 100% of severe disease. [10]
