Consumer edition active

Varicella Vaccine

ByMargot L. Savoy, MD, MPH, Lewis Katz School of Medicine at Temple University
Reviewed/Revised Modified Jul 2025
v16234258
VIEW PROFESSIONAL VERSION

The varicella vaccine helps protect against chickenpox (varicella), a very contagious infection caused by the varicella-zoster virus.

Chickenpox causes an itchy rash that looks like small blisters with a red base. In some people, the brain, lungs, and heart can become infected, resulting in serious illness or death. The virus remains in the body after the illness has resolved. If it is reactivated, it can cause shingles years later.

(See also Overview of Immunization.)

Vaccine Type

There are 2 varicella vaccines:

  • Standard dose varicella vaccine

  • Combination measles-mumps-rubella-varicella (MMRV) vaccine

The varicella vaccines are live-attenuated vaccines, which means they contain a weakened (attenuated) but still live version of the varicella-zoster virus. Because the virus is weakened, it can cannot cause chickenpox, but it does trigger a strong response from a person's immune system (see Active immunization).

Dose of and Recommendations for Varicella Vaccine

The varicella vaccines are given as an injection under the skin.

People who should get this vaccine

Varicella vaccine is a routine childhood vaccination (see CDC: Recommended Immunizations for Birth Through 6 Years Old, United States, 2025). Two doses are given: 1 at age 12 to 15 months and 1 at age 4 to 6 years.

Children who are 12 months to 12 years of age might be given 1 dose of the MMRV combination vaccine that protects against measles, mumps, rubella, and varicella.

Varicella vaccine is also recommended for all people 13 years old and older who have not had chickenpox or the vaccine. They are given 2 doses at least 4 weeks apart (see CDC: Chickenpox Vaccination).

Two doses of the varicella vaccine are recommended particularly for people who do not have documented or verified evidence of immunity and are likely to be exposed to or spread varicella:

  • Health care workers

  • Household contacts of people who have a weakened immune system

  • People who live or work in places where exposure or spread is likely (for example, teachers, students, child care workers, residents and employees of institutions, inmates and employees of correctional institutions, and military personnel)

  • People of childbearing age who are not pregnant

  • Adolescents and adults living in households with children

  • International travelers

People who should not get this vaccine

People who have had a serious, life-threatening allergic reaction (such as an anaphylactic reaction) after a previous dose of varicella vaccine or to an component in the vaccine (including the antibiotic neomycin, gelatin, or both) should not receive it.

Because the vaccine contains live virus, it is not given to pregnant people, people with a weakened immune system or a parent, brother, or sister with a history of immune system problems, or people with cancer of the bone marrow or lymphatic system.

The following people might not receive the vaccine:

  • People who are taking specific antiviral medications (acyclovir, famciclovir, or valacyclovir) or aspirin

  • People who recently received blood products

  • People who have a moderate to severe temporary illness

If people have a temporary illness, doctors usually wait to give the vaccine until the illness resolves.

Children who have HIV infection should not receive the combination MMRV vaccine, but if their HIV infection is well-controlled with medications, they may receive the standard dose varicella vaccine.

Certain conditions may affect whether and when people can be vaccinated (see also CDC: Who Should NOT Get Vaccinated With These Vaccines?).

Side Effects of Varicella Vaccine

The varicella vaccine is very safe, and common side effects are mild. Side effects may include pain, swelling, and redness at the injection site.

Occasionally, a mild chickenpox-like rash develops is a few people. People who develop this rash after the vaccine should diligently avoid contact with people who have a weakened immune system until after the rash resolves.

Taking aspirin and related medications (salicylates) after vaccination can cause a rare but serious disorder called Reye syndrome in children under 16 years old. Thus, children in this age group should not be given these medications for 6 weeks after vaccination.

For more information about side effects, see the package inserts.

More Information

The following English-language resources may be useful. Please note that The Manual is not responsible for the content of these resources.

  1. Centers for Disease Control and Prevention (CDC): Varicella (chickenpox) vaccine information statement

  2. European Centre for Disease Prevention and Control (ECDC): Varicella: Recommended vaccinations

Test your KnowledgeTake a Quiz!
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID