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Immunization

COVID-19 vaccines – viral vector-based

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​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Immunization protects you from dis​ease.
​​Get protected, get immuniz​​ed.

  • Vaccines make your immune system stronger. They build antibodies to help prevent diseases.
  • Immunization is safe. It's much safer to get immunized than to get this disease.​​
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What are COVID-19 vaccines?

COVID-19 vaccines protect against the SARS-CoV-2 virus (also known as COVID-19). The virus causes an infection in the lungs and airways and is a type of respiratory illness. In some cases, the infection can cause problems with other organs or other parts of the body. Go to ahs.ca/covid to learn more about COVID-19.

The following COVID-19 vaccines are approved for use in Canada:

  • mRNA vaccines: Pfizer-BioNTech (Comirnaty) and Moderna (SpikeVax)
  • viral vector-based vaccines: AstraZeneca (Vaxzevria)/COVISHIELD and Janssen (Johnson & Johnson)
  • protein-based vaccine​: Novavax (Nuvaxovid)
  • plant-based vaccine: Medicago (Covifenz)

The Pfizer-BioNTech, Moderna, Janssen, and Novavax vaccines are available in Alberta.

Who can get a viral vector-based COVID-19 vaccine?

Everyone is at risk of COVID-19. You can get a viral vector-based COVID-19 vaccine if you’re age 18 years or older and you can’t have or don’t want an mRNA or protein-based COVID-19 vaccine. COVID-19 vaccines are free.

Do I need a vaccine if I've already had COVID-19?

If you've already had COVID-19, it's not yet known how long your protection will last or how much protection you'll have against variants. It's important to get a COVID-19 vaccine even if you've already had the virus.

The vaccine may give you better protection if you wait a while after having COVID-19 and then get a vaccine. How long to wait depends on your health history and whether or not you've already had doses of COVID-19 vaccine.

If you've had COVID-19 in the past 90 days, check with your healthcare provider about when to get a COVID-19 vaccine.

How well do COVID-19 vaccines work?

How well the vaccines work against COVID-19 is different for each variant. COVID-19 vaccines are the best way to lower your risk of getting COVID-19 or getting very sick from it.

The mRNA vaccines give the best protection. The protein-based vaccine gives more protection than the viral vector-based vaccines. However, all the vaccines work very well to lower your risk of getting seriously ill and needing to be in the hospital.

Even if you’ve had a COVID-19 vaccine, it’s still important to follow public health measures to prevent the virus from spreading. Go to ahs.ca/covid for the most up-to-date information.

How many doses of viral vector-based COVID-19 vaccine do I need?

Primary series

If you got the AstraZeneca/COVISHIELD vaccine (no longer available in Alberta), you need a second dose of a COVID-19 vaccine to be considered fully immunized. These doses are called your primary series.

If you get the Janssen vaccine, at this time you need only 1 dose. However, it's likely that in the future you'll need a second dose of a COVID-19 vaccine for better protection and to complete your primary series.

For some people, 2 doses may not give enough protection. You may need a third dose to complete your primary series if you have a health problem that weakens your immune system. For example:

  • You've had or will have a an organ or stem cell transplant.
  • You have kidney disease and need dialysis.
  • You have acquired immunodeficiency syndrome (AIDS).
  • You take certain medicines that weaken your immune system.

Studies have shown that a third dose may provide better protection for adults with a weak immune system.

Booster doses

If you are age 18 years or older, you should get an extra (booster) dose 5 months after your primary series. A booster dose will give you more protection.

A second booster dose is recommended for some people who are at high risk of serious disease. This will provide better and longer protection. You can get a second booster dose if it has been at least 5 months since your first booster dose and you:

  • are age 70 years or older
  • live in a seniors living facility
  • are Indigenous and are age 65 years or older

Go to alberta.ca/covid19-vaccine​ to book an appointment for your booster dose.

Doses for travel

If you’re travelling outside of Canada, you may be able to get additional doses. This is only if your destination requires you to have a certain COVID-19 vaccine series or a dose within a certain time.​

Can I get a viral vector-based COVID-19 vaccine if I’m pregnant or breastfeeding?

Yes, you can get a viral vector-based COVID-19 vaccine if you’re pregnant or breastfeeding. However, research shows that mRNA vaccines are the safest type of COVID-19 vaccines to get during pregnancy. There is more to learn about getting a viral vector-based COVID-19 vaccine when you are pregnant or breastfeeding.

When you’re pregnant, you have a higher risk of getting very sick from COVID-19. Getting a COVID-19 vaccine lowers your risk of getting seriously ill from the virus.

If you’re pregnant or breastfeeding, it is recommended that you talk to your healthcare provider before getting a viral vector-based COVID-19 vaccine.

Where can I get a COVID-19 vaccine?

Go to ahs.ca/covidvaccine to find out where and when you can get a COVID-19 vaccine.

Are there side effects from the viral vector-based COVID-19 vaccine?

There can be side effects from the Janssen COVID-19 vaccine​, but they tend to be mild and go away in a few days. Side effects may include:

  • redness, swelling, or feeling sore where you had the needle
  • feeling tired, unwell or have a headache
  • a fever or chills
  • body aches, sore joints, or pain in your legs or arms
  • feeling sick to your stomach (nausea), vomiting (throwing up), or loose stool (diarrhea)

Current information shows that there’s a similar risk of side effects after a first, second, or additional dose of a viral vector-based vaccine. Research continues to find out more about the risk of side effects after additional doses.

It’s important to stay at the clinic for 15 minutes after your vaccine. Some people may have a rare but serious allergic reaction called anaphylaxis. If anaphylaxis happens, you’ll get medicine to treat the symptoms.

It’s rare to have a serious side effect. Call Health Link at 811 to report any serious or unusual side effects.

What rare events have been reported after getting the AstraZeneca/COVISHIELD or the Janssen vaccines?

Research is still happening to learn more about the risk of rare events after getting the AstraZeneca/COVISHIELD (no longer available in Alberta) or Janssen vaccines. It’s not yet known if having a history of certain health problems puts you at higher risk of rare events after having these vaccines.

Your risk of getting seriously ill from COVID-19 is much higher than your risk of having a rare event after these vaccines. Go to COVID-19 Vaccine Frequently Asked Questions for more information.

Blood clots, low platelets, bleeding

There have been very rare reports of blood clots, low levels of platelets (these help your blood to clot), and bleeding after getting either the AstraZeneca/COVISHIELD or the Janssen vaccines.

These events happened 4 to 28 days after getting the vaccine. The risk of these events after getting the AstraZeneca/COVISHIELD vaccine is about:

  • 1 in 55,000 after the first dose
  • 1 in 600,000 after the second dose

The risk of these events after getting the Janssen vaccine is about 3 in 1 million.

Talk to your healthcare provider if you have a condition that puts you at risk for blood clots or if you’ve ever had immune thrombocytopenia (ITP). ITP is when your immune system attacks the blood cells you need for normal blood clotting and causes bleeding.

If you have any of the following symptoms within 42 days of being immunized, get medical help right away:

  • trouble talking or moving a part of your body
  • shortness of breath
  • chest pain
  • severe swelling, pain, or a colour change in your arm or leg
  • stomach pain that doesn’t go away
  • a severe headache that doesn’t go away
  • blurry vision
  • seizures

Capillary leak syndrome

There have been very rare reports of capillary leak syndrome (CLS) within the first few days after getting the AstraZeneca/COVISHIELD or Janssen vaccines. In some reported cases, the person had a history of CLS. CLS is a serious condition that causes fluid to leak from the small blood vessels (capillaries). This causes sudden swelling of the arms and legs, sudden weight gain, and low blood pressure causing you to feel faint. CLS can cause death. Talk to your healthcare provider if you have any history of CLS. Get medical help right away if you have any of these symptoms.

Guillain-Barre syndrome

There have been very rare reports of Guillain-Barre syndrome (GBS) up to 42 days after getting the AstraZeneca/COVISHIELD or Janssen vaccines. GBS is a serious condition that causes pain or numbness, muscle weakness, and in severe cases, paralysis. Most people fully recover from GBS but some may continue to have symptoms. GBS can cause death. The risk of GBS after getting either AstraZeneca/COVISHIELD or Janssen vaccine is about 1 in 100,000. Get medical help right away if you have any of these symptoms.​

How can I manage side effects?

To help with soreness and swelling, put a cool, wet cloth over the area where you had the needle.

There is medicine to help with a fever or pain. Check with your doctor or pharmacist if you’re not sure what medicine or dose to take. Follow the directions on the package.

Some people with health problems, such as a weak immune system, must call their doctor if they get a fever. If you’ve been told to do this, call your doctor even if you think the fever is from the vaccine.

What vaccine will I get for my primary series?

You will get an mRNA COVID-19 vaccine for your primary series. If you can’t get or don’t want this type of vaccine, you can get the protein-based vaccine or the viral vector-based vaccine if you’re age 18 years or older.

Usually you get the same vaccine for all your doses. If your first-dose vaccine isn’t available or you can’t have it, you can get a different COVID-19 vaccine for your next dose.

Whichever vaccine you get to complete your primary series protects you against COVID-19.

Talk to your healthcare provider about which vaccine is best for you.

Go to ahs.ca/seconddose​ for more information.

What vaccine will I get for my booster or additional dose?

You will get an mRNA vaccine for any booster or additional doses. If you can’t get or don’t want an mRNA vaccine, you can get the protein-based vaccine​ if you are age 18 years or older.

The mRNA vaccines are licensed for first booster doses for people age 18 years or older who completed their primary series at least 6 months ago.

In other cases, the vaccine isn’t licensed for more than 2 doses. But vaccine experts support this in certain situations. This is called “off-label use.”

Getting more than 2 doses of a COVID-19 vaccine is off-label use if:

  • You are age 5 to 17 years.
  • You get a third dose sooner than 6​ months after your second dose.
  • You get a fourth or fifth dose.
  • You get the protein-based vaccine or a viral vector-based vaccine as a third dose, booster dose, or additional dose.

Talk to your healthcare provider about which vaccine you can get and when to have your doses.

What vaccine is recommended for people with a weak immune system?

Research has shown mRNA vaccines provide the best protection for people with a weak immune system. Talk to your healthcare provider about which vaccine is best for you.

What if I had or am getting another type of vaccine?

You can get any vaccine at the same time as, any time before, or any time after a viral vector-based ​COVID-19 vaccine.

Who should not get a viral vector-based COVID-19 vaccine?

You may not be able to get a viral vector-based COVID-19 vaccine if you:

  • have an allergy to any part of the vaccine
  • had a severe (serious) or unusual side effect after this vaccine or one like it
  • have a history of capillary leak syndrome (CLS)
  • are under age 18 years

Always tell your healthcare provider if you have allergies or if you've had a side effect from a vaccine in the past.

Check with your healthcare provider about when you can get a viral vector-based COVID-19 vaccine if you have had COVID-19 or have been treated for COVID-19 in the last 90 days.

Be sure to talk to your doctor before you get a viral vector-based COVID-19 vaccine, if you:

  • have a weak immune system (because of a medicine you take or a health problem)
  • have an autoimmune disorder (like rheumatoid arthritis or lupus)
  • have had a stem cell or organ transplant
  • have a history of immune thrombocytopenia (ITP)
  • are at higher risk of blood clots

Facts about COVID-19

What is COVID-19?

COVID-19 is a new strain of coronavirus that’s caused a worldwide pandemic. The virus causes an infection in the lungs and airways and is a type of respiratory illness. Symptoms may include:

  • a fever
  • a cough
  • shortness of breath
  • a sore throat
  • a runny nose
  • loss of sense of smell or taste

Most people have only mild symptoms or no symptoms at all. But if you’re an older adult or have other health problems, you can get very sick and may need care in a hospital. In serious cases, COVID-19 can cause a type of lung infection called pneumonia. Pneumonia makes it hard to breathe without help and can even lead to death.

Go to COVID-19: How to manage symptoms​ for a list of all symptoms that may be related to COVID-19.

How does it spread?

COVID-19 spreads:

  • when an infected person sneezes, coughs, or talks
  • if you breathe in the virus
  • if you touch something that has the virus on it (like hands or a doorknob) then touch your eyes, mouth, or nose

It’s important to know that you and others can spread COVID-19 before symptoms start.

Go to ahs.ca/covid to find out more.

How can I prevent COVID-19 from spreading?

To prevent COVID-19 from spreading:

  • get immunized
  • wash your hands with warm water and soap or use an alcohol-based hand sanitizer often
  • don’t touch your face, nose, or mouth with unwashed hands
  • cover your cough or sneeze into your arm or a tissue, not your hand
  • stay home when you’re sick
  • avoid close contact with people who are sick

If you think you’ve had contact with COVID-19 or have symptoms, take the COVID-19 Self-Assessment at ahs.ca/covidscreen.

More information

Current as of: May 12, 2022

Author: Provincial Immunization Program, Alberta Health Services