Chickenpox is an infectious disease caused by the varicella-zoster virus. People who get the virus often develop a rash of spots that look like blisters all over their bodies. These blisters develop into cloudy sores, which finally become dry brown crusts. Chickenpox is usually more severe in adults and very young infants than children. Winter and spring are the most common times of the year for chickenpox to occur. The disease typically makes children tired and slightly feverish.

The varicella vaccine (Varivax) is predicted to be 70 to 90 percent effective in preventing the disease This vaccine is generally recommended for toddlers between ages 12 to 18 months who have not had chicken pox, as well as older children, adolescents, and adults who may be exposed.

• Chickenpox vaccine may be given at the same time as other vaccines.
• Most children between 12 and 18 months of age group should have one dose of chickenpox vaccine.
• Many doctors will give the vaccine at 11 or 12 years of age to children in need. However, vaccine may be given any time between 19 months and 12 years. Your doctor or clinic can tell you whether your child should be vaccinated.
• Some people 13 or older who have not had chickenpox or gotten chickenpox vaccine should get two doses of the vaccine 4 to 8 weeks apart

Persons with weakened immune systems and those with life-threatening allergies to gelatin or the antibiotic neomycin should not receive this vaccine. Pregnant women should not receive this vaccine.