Below is an instruction from Human. Write a response.
    ### Instruction:
    How to prevent Varicella (Chickenpox) Vaccination ?
    ### Response:
    At a Glance 
 
Vaccine-preventable disease levels are at or near record lows. Even though most infants and toddlers have received all recommended vaccines by age 2, many under-immunized children remain, leaving the potential for outbreaks of disease. Many adolescents and adults are under-immunized as well, missing opportunities to protect themselves against diseases such as Hepatitis B, influenza, and pneumococcal disease.
    