​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

Print Resize text

Content Editor

Varicella (chickenpox)

Learn about varicella, who is at risk, and how it spreads.

About varicella

Varicella is a virus that can cause a fever and an itchy rash that looks like small water-filled blisters. It spreads easily through the air by coughing, sneezing, or by touching open blisters.

It is usually mild, but it can be more serious and cause:

  • skin infections
  • pneumonia (a type of lung infection)
  • blood infections
  • other deadly infections

Learn more about varicella.

After you get varicella, the virus stays in your body. It can become active again and cause shingles, which is a painful skin rash.

Who is most at risk?

People with the highest risk of serious infections from varicella are:

  • newborns
  • adults
  • people with weakened immune systems

How it spreads

Varicella spreads easily through the air by coughing, sneezing, or touching open blisters. You can spread varicella before you get the rash.

Coughing

Sneezing

Touching open blisters

Pregnancy

If you are pregnant and get varicella, there is a small risk of having a baby born with:

  • a low birthweight
  • eyesight (vision) problems
  • scars on the skin
  • a health condition, such as poor development of the brain, an arm, or a leg

If you get varicella a few days before or after you have your baby, the baby has a high risk of getting very sick or dying.

Current as of: August 31, 2026
Author: Communicable Disease Control, Primary Care Alberta
Our work takes place on historical and contemporary Indigenous lands, including the territories of Treaty 6, Treaty 7 & Treaty 8 and the homeland of the Métis Nation of Alberta and 8 Métis Settlements. We also acknowledge the many Indigenous communities that have been forged in urban centres across Alberta.