What Is Chickenpox (Varicella)?

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

Chickenpox 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 3 months apart.

Kids 13 years or older who have not had either chickenpox or the vaccine need two vaccine doses 1 to 2 months apart.

Why Is the Chickenpox Vaccine Recommended?

The chickenpox 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 of Chickenpox Immunization

Possible mild effects are tenderness and redness where the shot was given, fever, tiredness, and a varicella-like illness. There is a very small chance of an allergic reaction with any vaccine.

A rash can happen 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 Chickenpox Immunization

The varicella vaccine is not recommended if if your child:

• had a severe allergic reaction to a previous dose of varicella vaccine, or components of the vaccine. which include gelatin and the antibiotic neomycin
• has recently received gamma globulin or a blood transfusion
• has a disorder that affects the immune system (such as cancer)
• is taking steroids or other medicine that weakens the immune system
• is undergoing chemotherapy or radiation therapy

Talk to your doctor about whether the vaccine is a good idea if your child:

• is currently sick. Generally, simple colds and other minor illness should not stop your child from getting a vaccine.
• takes aspirin. People who take aspirin should stop for 6 weeks before getting the chickenpox vaccine.
• has received any other vaccines in the past month because some can interfere with how well the chickenpox vaccine will work
• has ever had a low platelet count

Your doctor may decide 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 Chickenpox Immunization

Check with your doctor to see if you can give either acetaminophen or ibuprofen for pain or fever and to find out the appropriate dose.

When Should I 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: 01-03-2019