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Diseases reference index «Chickenpox vaccine»

Chickenpox vaccine

This vaccine protects against chickenpox, a disease caused by the varicella-zoster virus.


Chickenpox is caused by the varicella-zoster virus (VZV). It is very common and highly contagious, occurring more often in the winter and spring. Most of the time, the infection is mild and not life-threatening. However, there are thousands of cases each year in which people become seriously ill, requiring hospitalization, and some children do die from it.

The chickenpox vaccine works very well in preventing the disease. A small number of people who get the vaccine will still get chickenpox. However, they usually have a milder case than those seen in persons who did not receive the vaccine.


The American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC) recommend that children receive two doses of the traditional chickenpox vaccine.

  • The first dose should be given when the child is 12 - 15 months old.
  • Children should receive the second dose when they are 4 – 6 years old. However, the second dose can be given before age 4, as long as as 3 months have passed since the first dose.
  • People 13 and older who have not received the vaccine and have not had chickenpox should get 2 doses 4 to 8 weeks apart.
  • People 13 and older who have had a previous dose and have not had chickenpox should receive a second dose.


The side effects from the chickenpox vaccine are generally minor. Some of the mild possible side effects include:

  • Fever
  • Pain and swelling in the shot location
  • A mild rash

Only in very rare instances have more moderate or severe reactions been reported, including:

  • Seizures (less than 1 out of 1,000 children)
  • Pneumonia (very rare)
  • Anaphylaxis (a severe allergic reaction; very rare)

Other reactions, such as low blood counts and brain involvement, are so rare that their link to the vaccine is questionable.


  • Pregnant women should not receive the vaccine. Women who have received the vaccine should wait at least 1 month before getting pregnant. (Woman planning pregnancy should be screened for immunity using history or laboratory testing.)
  • Children or adults who have a weakened immune system as a result of HIV/AIDS, cancer, organ transplants, or other factors should not be vaccinated for chickenpox.
  • Children or adults who are allergic to the antibiotic neomycin or gelatin should not receive this vaccine.
  • Children or adults taking steroids for any condition should consult with their doctor about the proper timing of chickenpox vaccine.
  • Anyone who has recently received a blood transfusion or other blood product (including gamma globulin) should consult with their doctor about the proper timing of the chickenpox vaccine.
  • Children receiving aspirin or other salicylates should not receive this vaccine because of the theoretical risk of Reye syndrome.


  • You are not sure if the chickenpox vaccine should be given
  • Any moderate to severe side effects appear after the injection
  • Any symptoms occur after the vaccine that alarm you
  • You have any other questions before or after receiving the vaccine

Alternative Names

Varicella zoster virus vaccine; Varivax; Vaccine - chickenpox