Get protected, get immunized.
- 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.
What is Imvamune?
Imvamune is a vaccine that protects against
orthopoxvirus infections such as mpox (previously called monkeypox) and smallpox. As of the date at the bottom of this information, there are no cases of smallpox in Canada, but there are cases of mpox.
Imvamune is approved for use in Canada.
What is mpox?
Mpox is a rare disease caused by the mpox virus. It can infect humans. It’s usually mild and most people recover on their own after a few weeks. However, some people can get very sick and even die. Early symptoms may include:
- swollen lymph nodes
- muscle pain
- joint pain
- back pain
- exhaustion (feeling very tired)
Most people with mpox infection will get a rash or sores which can be on the hands, feet, mouth, and genitals. The rash can last 14 to 28 days. You can spread mpox to others from the time your symptoms start until the rash goes away and your skin heals.
Who is most at risk?
You’re at risk if you have close contact with someone who has mpox (for example, you live with the person or have sexual contact with them). You may be at higher risk of getting very sick if you:
- have a weak immune system
- are under age 18 years
- are pregnant
How does it spread?
Mpox spreads through close contact with someone who has mpox. It may also spread if you have contact with bedding, sheets, or clothing that touches the rash and has virus on it. The virus enters the body through broken skin or your eyes, nose, or mouth.
How can I prevent mpox from spreading?
Here’s what you can do to prevent mpox from spreading:
- 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 or have skin sores.
- Practise safer sex (use condoms or other barriers against skin-to-skin contact).
- Avoid close contact with people who have mpox and their clothing, towels, or bedding.
Who should get Imvamune?
You may be able to get this vaccine if you have a higher risk of being exposed to mpox.
You may have a higher risk if you identify as part of the men who have sex with men (MSM) community or have had or are planning to have sexual contact with someone who identifies as MSM, and 1 of the following applies to you:
- You or your sexual partner are planning to have more than 1 sexual partner or have had more than 1 sexual partner in the last 90 days.
- You are planning to have sexual or skin-to-skin contact at a venue such as a bath house, sex club, or sex party, or you have had sexual contact at this type of venue in the last 90 days.
- You have had a sexually transmitted infection in the last year.
You may also have a higher risk if you:
- are a sex worker
- went to or worked at a venue where people have sexual or skin-to-skin contact (such as a bath house, sex club, or sex party) in the last 90 days
- work in a research lab and have direct contact with the orthopoxvirus as part of your work
You should also get this vaccine if you had close contact with someone who has mpox. It’s best to get this vaccine within 4 days of close contact, but you can get it up to 14 days after. Once your symptoms start, you can no longer get the vaccine.
Call Health Link at 811 to find out if you should get this vaccine.
Imvamune is licensed for people age 18 years or older. However, vaccine experts support using Imvamune for people of any age who are at high risk of being exposed to mpox or have had close contact with someone who has mpox. If you get the vaccine and are under age 18 years, this is called “off-label use.” There is limited information on the use of Imvamune in children. Studies done with similar vaccines show there were no safety concerns for children under age 18 years. Talk to your healthcare provider if you are under age 18 years before getting this vaccine.
How many doses do I need?
If you are getting the vaccine because you have a high risk of being exposed to mpox, you need 2 doses.
If you are getting the vaccine because you had close contact with someone who has mpox, you need at least 1 dose. You may need more doses depending on your risk of being exposed to mpox virus again and your immune system health.
If you have had smallpox vaccine in the past, you may need fewer doses of mpox vaccine.
Talk to your healthcare provider about how many doses you need.
How well does the vaccine work?
For Imvamune to work, you need to get it before mpox symptoms start. If you get Imvamune after contact with mpox virus, the vaccine can protect you from getting an mpox infection, or it can make the infection milder. If you have a weak immune system, the vaccine may not work as well.
Where can I get Imvamune?
If you think you may be at higher risk for being exposed to mpox, call Health Link at 811 to see if you can get the vaccine.
If you think you need the vaccine because of your work in a research lab, talk to your workplace health and safety department.
Public Health will contact you if you are identified as a close contact of a confirmed case of mpox. If Public Health decides that you need Imvamune, they will tell you where to go for the vaccine.
Are there side effects from Imvamune?
There can be side effects from Imvamune, but they tend to be mild to moderate and go away within 7 days. Side effects may include:
- at the area where you had the needle: redness, changes in skin colour, bruising, swelling, warmth, itching, a hard spot or small lump, or feeling sore
- feeling tired
- a headache
- a fever or chills
- body aches, sore joints
- pain in your arms or legs
- not feeling hungry or not wanting to eat (poor appetite)
- feeling sick to your stomach (nausea)
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 Imvamune?
There have been rare reports of cardiac (heart) symptoms after getting Imvamune. However, none were considered serious. There have also been reports of myopericarditis (an inflammation of both the heart muscle and lining around the heart) after other vaccines that protect against smallpox. However, no cases of myopericarditis after Imvamune have been reported. Get medical help
right away if you have any of these symptoms:
- shortness of breath
- chest pain
- a fluttering feeling in your chest (palpitations)
It is not known if having a history of myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the lining around the heart) after getting Imvamune or another smallpox vaccine puts you at higher risk of having these rare events. Talk to your healthcare provider before getting Imvamune if you have had these rare events after getting a smallpox vaccine or Imvamune.
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 if I had or am getting another type of vaccine?
It’s best not to get Imvamune at the same time as another vaccine so that you can watch for side effects. However, if you have been exposed to mpox, you should not wait to get Imvamune.
If you are at a high risk of being exposed to mpox, it is recommended to wait for 14 days after getting another vaccine before you get Imvamune, but it is not required. If you recently got a COVID-19 mRNA vaccine, it is recommended to wait for 4 weeks before you get Imvamune, but it is not required. There are no safety concerns, and both vaccines will still work to protect you.
If you got another vaccine in the last 4 weeks, talk to your healthcare provider about when you should get Imvamune.
After getting Imvamune, you should wait at least:
- 4 weeks before getting a COVID-19 mRNA vaccine
- 14 days before getting any other vaccine
Who should not get Imvamune?
You may not be able to get this vaccine if you:
- have an allergy to any part of the vaccine
- had a serious or unusual side effect after this vaccine or one like it
- have been diagnosed with an mpox infection during this outbreak (beginning in May 2022), because you are likely immune
Check with your doctor or a public health nurse before you get Imvamune.
You can still get the vaccine if you have a mild illness such as a cold or fever. However, if you have symptoms of an illness, you should stay home until you are feeling better, unless you have been exposed to mpox. If you have been exposed, you should get the vaccine right away.
You can get the vaccine if you have eczema (atopic dermatitis—a skin condition that makes your skin red and itchy). People with eczema are more likely to have serious side effects with other smallpox vaccines, but this has not been reported with Imvamune. If you have eczema and get Imvamune, you may be more likely to have common vaccine side effects or your eczema could get worse. Talk to your healthcare provider if you have questions.
There is more to learn about Imvamune and certain groups of people. Talk to your healthcare provider
before you get Imvamune if you:
- have a weak immune system (because of medicine you take or a health problem)
- are pregnant or breastfeeding
- are under age 18 years
- have a history of myocarditis or pericarditis after getting smallpox vaccine or Imvamune
I have a fear of needles. How can I prepare for my immunization?
Many adults and children are afraid of needles. You can do many things before, during, and after immunization to be more comfortable. Visit
Commitment to Comfort for tips to make immunization a better experience.
For more information about immunization