What Is Varicella?

Varicella, commonly called chickenpox, is a highly contagious infection. It is caused by the varicella zoster virus (VZV). It produces an itchy rash. It can cause serious complications, especially in adults, newborns, or people with weak immune systems.

VZV spreads from person to person by:

• Airborne droplets of moisture that contain the virus
• Direct contact with fluid from a varicella rash

It is most contagious just after the rash has broken out. It is also contagious 1-2 days before the rash erupts and until all of the blisters have crusted.

Symptoms include:

• Headache
• Fever
• General feeling of discomfort
• A rash of small, flat, red spots that become raised to form round, itchy, fluid-filled blisters

It takes about 10-21 days to develop varicella after contact with an infected person. The illness lasts 5-10 days. The rash usually develops on the face and trunk.

Treatment generally focuses on reducing itchiness, such as using anti-itch cream. Antibiotics may be used for rashes that become infected. Antiviral drugs might be considered for some patients.

Varicella can lead to scarring, pneumonia, and death in severe cases.

What Is the Varicella Vaccine?

Varicella vaccine is a live virus vaccine that is given by injection. The varicella vaccine can also be given in a combination vaccine called the MMRV. This protects against measles, mumps, rubella, and varicella.

Who Should Get Vaccinated and When?

The vaccine is recommended for most children aged 12-15 months. The second dose is given between ages 4-6 years.

The CDC recommends the following schedule for those who have not been vaccinated:

• Up to age 13 years—2 doses, with 3 months between the first and second dose
• 13 years and above—2 doses, with a minimum of 4 weeks between the first and second dose

If you are an adult who has not been fully vaccinated and have never had chickenpox, it is recommended that you get vaccinated. Talk to your doctor. If you have certain conditions, you will not be able to get the vaccine.

If you or your child has not been vaccinated but has been exposed to chickenpox, getting vaccinated within three days can help reduce the virus or offer protection from the infection.

What Are the Risks Associated With the Varicella Vaccine?

The varicella vaccine, like all vaccines, can cause problems, such as severe allergic reaction. The risk of serious harm or death is extremely small. Most people do not have any problems with the vaccine.

The most common complaints are:

• Soreness or swelling around the injection site
• Fever
• Mild rash

Shingles can happen after the vaccine, but it is much less common that shingles after the infection itself. Less commonly, seizure caused by fever, pneumonia, or other serious problems (such as low blood count) have been reported. There is some evidence that children are more likely to have seizures if they are given the MMRV vaccine as the first dose. The Centers for Disease Control and Prevention (CDC) recommends that parents be advised of the risk of fever and seizure. Parents should be given the option to choose the combined or separate vaccine.

Who Should Not Get Vaccinated?

You should not get the vaccine if you:

• Are ill—Wait until you feel better to get the shot
• Had varicella
• Had a life-threatening allergic reaction to gelatin, the antibiotic neomycin, or a previous dose of the varicella vaccine
• Are pregnant—Get the vaccine after you have given birth. Women who are trying to get pregnant should wait until 1 month after getting the shot to get pregnant.

Talk to your doctor before getting the vaccine if you have the following conditions:

• HIV/AIDS or another disease that affects the immune system
• Are being treated with medicines that affect the immune system (such as long-term steroids)
• Cancer
• Had a recent blood transfusion

What Other Ways Can Varicella Be Prevented Besides Vaccination?

Avoiding contact with people who have the virus can reduce the chance of getting it.

What Happens in the Event of an Outbreak?

In the event of an outbreak, people who have not had the virus or the vaccine should be vaccinated.

Chickenpox vaccine: What you need to know. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/vaccines/hcp/vis/vis-statements/varicella.html
Updated June 18, 2013. Accessed November 4, 2014.

Immunization schedules. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/vaccines/schedules/index.html
Updated January 31, 2014. Accessed November 4, 2014.

Klein NP, Fireman B, et al. Vaccine Safety Datalink. Measles-mumps-rubella-varicella combination vaccine and the risk of febrile seizures. Pediatrics. 2010;126(1):e1-e8.

Marin M, Broder KR, et al. Use of combination measles, mumps, rubella, and varicella vaccine: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2010;59(RR-3):1-12.

MMRV and febrile Seizures. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/vaccinesafety/Vaccines/MMRV/studyfeature.html
Updated February 7, 2011. Accessed November 4, 2014.

Varicella (chickenpox) vaccination. US Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/vaccines/vpd-vac/varicella/default.htm
Updated April 5, 2012. Accessed November 4, 2014.

10/14/2008 DynaMed’s Systematic Literature Surveillance
http://www.ebscohost.com/dynamed:
Macartney K, McIntryre P. Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults. Cochrane Database Syst Rev. 2008;(3):CD001833.

12/9/2013 DynaMed’s Systematic Literature Surveillance
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Weinmann S, Chun C, et al. Incidence and clinical characteristics of herpes zoster among children in the varicella vaccine era, 2005-2009. J Infect Dis. 2013:208(11):1859-1868.