What Is Varicella?

Varicella (chickenpox) is an infection caused by a virus. The virus spreads easily from person to person by:

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

The infection causes a rash that turns into itchy, fluid-filled blisters that scab and fall off. A severe infection can lead to more serious problems like scarring, pneumonia, and death. Newborns, adults, and people who have problems with how their immune system works are at greater risk of problems.

What Is the Varicella Vaccine?

The varicella vaccine is a live virus that is given by injection. The vaccine works by causing the body to produce its own protection against the virus.

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 children aged 12 to 15 months. A second dose is given between ages 4 to 6 years.

Older children, teens, and adults are advised to get 2 doses of the vaccine if they are not already immune to varicella.

What Are the Risks Associated With the Varicella Vaccine?

Common side effects are:

• Soreness, redness, or rash at the site of the injection
• Fever

Less common, but more serious side effects are:

• Pneumonia
• Severe allergic reaction
• Seizures linked to fever
• Infection of the brain or spinal cord

People who have problems with how their immune system works may get a life-threatening infection.

Some people who get the vaccine can get shingles years later. This is much less common after vaccination than after varicella.

Who Should Not Get Vaccinated?

People should not get the vaccine if they:

• Have had an allergic reaction to a previous dose of the vaccine
• Have severe, life-threatening allergies
• Are pregnant or think they might be pregnant
• Have problems with how their immune system works or has a close family member with a history of immune system problems
• Are taking salicylates, such as aspirin
• Have recently had a blood transfusion or received other blood products
• Have tuberculosis
• Have gotten any other vaccines in the past four weeks
• Had a life-threatening allergic reaction to gelatin, the antibiotic neomycin, or a previous dose of the varicella vaccine.

People who are moderately or severely ill should wait to get the vaccine.

What Other Ways Can Varicella Be Prevented Besides Vaccination?

The risk of this problem can be lowered by avoiding contact with people who have the virus.

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.