The varicella vaccine protects against chickenpox (varicella), a common and very contagious childhood viral illness.

Immunization Schedule

The varicella vaccine is given by injection when kids are between 12 and 15 months old. They receive a booster shot for further protection at 4 to 6 years of age.

Kids who are older than 6 but younger than 13 who have not had chickenpox also may receive the vaccine, with the two doses given at least 3 months apart.

Kids 13 years or older who have not had either chickenpox or the vaccine need two vaccine doses at least 1 month apart.

Why the Vaccine Is Recommended

The varicella vaccine prevents severe illness in almost all kids who are immunized. It's up to 85% effective in preventing mild illness. Vaccinated kids who do get chickenpox generally have a mild case.

Possible Risks

Serious reactions such as allergic reactions are extremely rare. Possible mild effects are tenderness and redness where the shot was given, fever, fatigue, and a varicella-like illness. A rash can occur up to 1 month after the injection. It may last for several days but will disappear on its own without treatment. There is a very small risk of febrile seizures after vaccination.

When to Delay or Avoid Immunization

The vaccine is not recommended if:

• your child is currently sick, although simple colds or other minor illnesses should not prevent immunization
• your child has had an allergic reaction to gelatin or to the antibiotic neomycin that required medical treatment

Talk to your doctor about whether being vaccinated is a good idea if your child:

• had a severe allergic reaction to a previous dose of varicella vaccine
• has recently received gamma globulin or a blood transfusion
• has a disorder that affects the immune system (such as cancer); is taking prednisone, steroids, or other immunosuppressive drugs; or is undergoing chemotherapy or radiation therapy

Your doctor may determine that the benefits of vaccinating your child outweigh the potential risks.

Pregnant women should not receive the chickenpox vaccine until after childbirth.

Caring for Your Child After Immunization

Pain and fever can be treated with acetaminophen or ibuprofen. Check with your doctor to see if you can give either medication and to find out the appropriate dose.

When to Call the Doctor

Call your doctor if:

• you aren't sure if the vaccine should be postponed or avoided
• there are problems after the immunization

Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: October 2012