Chickenpox vaccine


The chickenpox vaccine protects against chickenpox. This is a disease that causes a rash, blisters, and fever. Chickenpox is also called varicella.

Alternative Names

Immunization - chickenpox; Vaccine - VAR;Immunization - VAR; Varicella zoster vaccine


Chickenpox is caused by the varicella-zoster virus. The virus is very common and spreads very easily.

The chickenpox vaccine is called VAR for short. It is made from weakened chickenpox virus. After getting the vaccine, the body learns to attack the chickenpox virus if the person is exposed to it. As a result, it is unlikely the person will get sick with chickenpox.



VAR is one of the vaccines recommended for children. All states require proof that a child has received the vaccine before starting daycare, preschool, or kindergarten.

VAR is given to children as a series of two doses (shots). One dose is given at each of the following ages:

  • 12 to 15 months old
  • 4 to 6 years old

Persons 13 or Older

  • Those who have not received the vaccine and have not had chickenpox should get two doses (shots). The second dose should come at least 4 weeks after the first dose.
  • Those who have had one dose and have not had chickenpox should get a second dose.
  • Women who have received the vaccine should wait at least 1 month before getting pregnant.
  • Women who are planning to get pregnant should have a blood test that checks if they are protected against chickenpox.


  • Persons who received a dose of VAR and developed an allergy from it.
  • Pregnant women, including the 1 month before pregnancy.
  • Certain HIV-infected persons.
  • Persons whose immune systems are weakened by disease or medicines (such as after organ transplant).
  • Persons who are ill with something more severe than a cold or have a fever should reschedule their vaccination until after they are recovered. 


Most persons who get VAR have no problems from it. In other cases:

  • Mild rash may develop within a month of getting the vaccine. In very rare cases, the person spreads chickenpox to others.
  • Severe side effects can develop, including an allergic reaction to parts of the vaccine.

There is no proof that VAR is linked to the development of autism.

No vaccine works all of the time. It is still possible, though unlikely, to get chickenpox even after receiving all doses (shots) of VAR.


  • You are not sure if a person should get VAR
  • Severe side effects appear after getting the vaccine
  • You have questions or concerns about the vaccine


Centers for Disease Control and Prevention. Advisory Committee on Immunization Practices (ACIP) Recommended Immunization Schedules for Persons Aged 0 Through 18 Years and Adults Aged 19 Years and Older - United States, 2013. MMWR. 2013;62(Suppl1):1-19.

Centers for Disease Control and Prevention. Vaccine safety and adverse events. Available at Accessed April 19, 2013.

DeStefano F, Price CS, Weintraub ES. Increasing exposure to antibody-stimulating proteins and polysaccharides in vaccines is not associated with risk of autism. J Pediatr. 2013; DOI10.1016/j.peds.2013.02.001.

Institute of Medicine. Immunization Safety Review Committee. Imunization Safety Review: Vaccines and Autism. Washington, DC: The National Academies Press; 2004.

Orenstein WA, Atkinson WL. Immunization. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, Pa.: Elsevier Saunders; 2011:chap 17.

Review Date: 
Reviewed By: 
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.