About chickenpox

Chickenpox (varicella) is an illness caused by the varicella zoster virus. Symptoms include:

• blister-like rash
• itching
• slight fever
• fatigue

Chickenpox is easy to catch:

• It is spread through the air when someone who has the virus coughs or sneezes.
• It can also be spread by touching a blister or the liquid from the blister.
• Chickenpox is contagious 1 to 2 days before the rash begins and until all the blisters are crusted over.

Before widespread use of the chickenpox vaccine, there were about 350,000 new cases each year in Canada. Although the one-dose schedule of chickenpox vaccine has reduced disease and hospitalization, some children are still at risk of being infected after one dose. Two doses of chickenpox vaccine further protect against the disease and reduce hospitalizations and complications.

Chickenpox can cause problems such as:

• scarring of the skin
• skin or bone infections
• pneumonia

Serious illness, such as inflammation of the brain (encephalitis) can occur, but is rare. Chickenpox can also be dangerous for:

• people with weak immune systems
• pregnant women, as the unborn baby may develop birth defects or serious complications

In many people, the virus can become active again later in life and cause a painful rash called shingles.

Who should receive the vaccine

Children should receive 2 doses of chickenpox vaccine:

• first dose at 15 months of age
• second dose at 4-6 years of age (it is usually combined (MMRV) with measles, mumps and rubella)

If a dose is missed, your healthcare provider will discuss the “catch-up” schedule with you.

Who should not receive the vaccine

Children should not get the vaccine if they have:

• allergies to the vaccine or any component of the vaccine
• previously experienced an allergic reaction to the varicella vaccine

Please consult with your healthcare provider if your child has:

• a weakened immune system or takes medications that suppress the immune system
• received blood or blood products
• a moderate to severe illness

Vaccine safety

As with most vaccines, side effects are usually mild and last for only a few days after getting the needle. Some common side effects include:

• redness
• swelling and tenderness in the area where the vaccine was given
• low-grade fever

Some children might get a very mild chickenpox-like rash up to 26 days they get the vaccine. Severe reactions are rare.

Deciding not to vaccinate

The vaccine is required by law:

• to attend school (Immunization of School Pupils Act Amendment, 2014) if your child was born in or after 2010
• to attend licensed child care (Child Care and Early Years Act (2014) (external link))

Your child will be at risk of getting chickenpox if you decide not to vaccinate. Parents who choose not to vaccinate for personal choice must do the following:

• complete a Statement of Conscience or Religious Belief (external PDF)
• have the legal document notarized
• attend a vaccine education session at Halton Region Health Department (for school attendance only)

Parents who choose not to vaccinate for medical reasons must do the following:

• have a doctor fill out a medical exemption form
• bring the form to the Halton Region Health Department

More information

If you have questions, speak to your healthcare provider or call 311  .