Varicella vaccination provides effective protection against varicella (chickenpox). It is not known how long protection against varicella lasts. But, live-virus vaccines, like the varicella vaccine, usually provide long-lasting immunity.
(See also Overview of Immunization.)
The varicella vaccine contains an attenuated wild strain of varicella and trace amounts of gelatin and neomycin. It is available as a single-antigen vaccine or as a combination vaccine with measles, mumps, rubella (MMRV).
Varicella vaccine is a routine childhood vaccine (see Table: Recommended Immunization Schedule for Ages 0–6 Years).
Single-antigen varicella vaccine also is recommended for
Evidence of immunity consists of one of the following:
The varicella vaccine is recommended particularly for people who do not have evidence of immunity and are likely to be exposed to or transmit varicella, including the following:
Health care workers
Household contacts of immunocompromised people
People who live or work in places where exposure or transmission is likely (eg, teachers, students, child care workers, residents and employes of institutional settings, inmates and employees of correctional institutions, military personnel)
Women of childbearing age who are not pregnant
Adolescents and adults living in households with children
Postexposure vaccination with the single-antigen varicella vaccine is recommended for children with no evidence of immunity and should be offered to adults with no evidence of immunity. The vaccine is effective in preventing or ameliorating disease if it is given within 3 days and possibly up to 5 days after exposure; however, the vaccine should be given as soon as possible. If exposure to varicella does not cause infection, postexposure vaccination should induce protection against subsequent exposures, even if the vaccine is given > 5 days postexposure.
Varicella-zoster immune globulin (see table Immune Globulins and Antitoxins Available in the US) is recommended for postexposure prophylaxis in people who have no evidence of immunity, are at increased risk of severe varicella, and/or have contraindications to the varicella vaccine. These people include
Immunocompromised people without evidence of immunity
Pregnant women without evidence of immunity
Neonates whose mothers developed varicella within 5 days before to 2 days after delivery
Hospitalized premature infants who were born at ≥ 28 weeks gestation and whose mothers do not have evidence of immunity to varicella
Hospitalized premature infants who were born at < 28 weeks gestation or who weigh ≤ 1000 g at birth, regardless of their mother's evidence of immunity to varicella
Contraindications for varicella vaccine include
A severe allergic reaction (eg, anaphylaxis) after a previous dose of the vaccine or to a vaccine component
Known severe primary or acquired immunodeficiency (eg, due to leukemia, lymphomas, solid tumors, tumors that affect bone marrow or the lymphatic system, AIDS, severe HIV infection, treatment with chemotherapy, or long-term use of immunosuppressants)
Unless people are known to be immunocompetent, family history of 1st-degree relatives who have congenital hereditary immunodeficiency
Confirmed or suspected pregnancy
The single-antigen varicella vaccine may be given to children aged 1 to 8 years who have HIV infection if their CD4 percentage is ≥ 15; it may be given to those > 8 years if their CD4 count is ≥ 200/mcL.
Precautions with varicella vaccine include
Moderate or severe acute illness with or without fever (vaccination is postponed until illness resolves)
Recent (within 11 months) treatment with blood products that contain antibody (specific interval depends on the product)
Use of specific antiviral drugs: acyclovir, famciclovir, or valacyclovir (if possible, these drugs are stopped 24 hours before vaccination and are not resumed for 14 days after vaccination)
Breastfeeding is not a contraindication to vaccination. Women who are breastfeeding and do not have evidence of immunity can be vaccinated postpartum and continue breastfeeding.
The varicella vaccine dose is 0.5 mL given subcutaneously in 2 doses: at age 12 to 15 months and at age 4 to 6 years. If children, adolescents, or adults have been given only 1 dose, a catch-up dose is recommended. The recommended minimum interval between the 1st dose and the catch-up 2nd dose is 3 months for children aged ≤ 12 years and 4 weeks for people aged ≥ 13 years; the 2nd dose may be given at any interval longer than the minimum.
If adults think that they have not had varicella or are likely to be exposed to or to transmit varicella, levels of protective antibodies should be measured to check for evidence of immunity and thus determine the need for vaccination.
No immune globulins, particularly varicella-zoster immune globulin, should be given within 5 months before or 2 months after vaccination because immune globulins may prevent development of protective antibodies.
Eligible children with HIV infection are given 2 doses of single-antigen varicella vaccine 3 months apart. Because impaired cellular immunity increases the risk of complications after vaccination with a live vaccine, these children should be encouraged to return for evaluation if a varicella-like rash develops after vaccination.
Prenatal assessment of women for evidence of varicella immunity is indicated. Birth before 1980 is not considered evidence of immunity for pregnant women. After completion or termination of pregnancy, women who do not have evidence of immunity should be given the 1st dose of vaccine before discharge and the 2nd dose 4 to 8 weeks later, usually at the postpartum visit. Women should be advised to avoid becoming pregnant for 1 month after each dose.
Most adverse effects are minimal and include transient pain, tenderness, and redness at the injection site. Occasionally, within 1 month of vaccination, a mild maculopapular or varicella-like rash develops in 1 to 3% of people who are vaccinated. Vaccine recipients who develop this rash should diligently avoid contact with immunocompromised people until it resolves. Spread of the virus from vaccine recipients to susceptible people is rare but can result in severe problems, including pneumonia, hepatitis, severe rash, and shingles with meningitis. However, such problems rarely develop.
Because Reye syndrome can develop, recipients < 16 years should avoid salicylates for 6 weeks after the vaccine is given.
The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.