Chickenpox

print this page

Did you know?

Chickenpox is usually a mild disease but it can be serious, especially in newborns, teenagers, adults, pregnant women, and those with weakened immune systems. 

Nathan's Story

Nathan's mom shares her story about the stroke Nathan suffered after becoming infected with chickenpox.

The disease 

  • Chickenpox (varicella) is an infection caused by the varicella-zoster virus.
  • Chickenpox is spread through the air when an infected person sneezes or coughs. It can also be spread through contact with the fluid from chickenpox blisters, or the saliva of a person who has chickenpox. A pregnant woman with chickenpox can pass it to her baby before birth.
  • Children with chickenpox have an average of 350 red, itchy blisters.
  • Infection in newborns, teenagers, adults, pregnant women, and those with weakened immune systems is more severe.
  • Complications from chickenpox include pneumonia (an infection of the lungs), encephalitis (swelling of the brain), and bacterial infections of the skin. Encephalitis can lead to seizures, deafness or brain damage.
  • Infection early in pregnancy can result in a baby being born with birth defects. This is known as congenital varicella syndrome (CVS). Chickenpox can also cause miscarriage or stillbirth.
  • About 1 in 3,000 adults will die from chickenpox.

The vaccine

  • The chickenpox vaccine is given to children as a series of two doses. The first dose is given at 12 months of age and the second dose at 4 to 6 years of age. Children 4 - 12 years of age who also need protection against measles, mumps or rubella can get their second dose of the chickenpox vaccine as the combined Measles, Mumps, Rubella and Varicella (MMRV) vaccine.  
  • The chickenpox vaccine is also provided to students in Grade 6 who have not received two doses of the vaccine. Most grade 6 students would have received 1 dose of the vaccine on or shortly after their 1st birthday and will only need 1 more dose of vaccine. Grade 6 students who have never received the vaccine should get 2 doses.
  • The vaccine is also available as a series of 2 doses to people 13 years of age or older who have not been immunized. 
  • People do not need to get the chickenpox vaccine if they had chickenpox or shingles at 1 year of age or older and the disease occurred before 2004 or it was confirmed by a lab test.
  • People who had chickenpox before their 1st birthday should still get the vaccine as they may not have developed a long-lasting immunity and could get chickenpox again.
Date last updated: 
Wednesday, Sep 05, 2018
Date last reviewed: 
Wednesday, Nov 01, 2017