Mpox vaccine

Imvamune® vaccine is approved in Canada for protection against smallpox, mpox, and other orthopoxvirus-related illnesses. The vaccine contains weakened virus and cannot make you sick.

Currently, in Ontario, one dose of Imvamune® can be received as:

1. Pre-Exposure Prophylaxis (PrEP ), which means receiving the vaccine prior to any mpox exposure (for those who are likely to be exposed).
2. Post-Exposure Prophylaxis (PEP), which means receiving the vaccine after a potential exposure.

The vaccine should ideally be given within 4 days but can be given up to 14 days after the last exposure.

If you think you have been exposed to mpox, contact your local public health unit to see if you may be eligible to receive the vaccine. Imvamune® is not a treatment for mpox.

Eligible individuals who want to receive PrEP should contact Public Health Sudbury & Districts at 705.522.9200, ext. 482 (toll-free 1.866.522.9200) or Réseau ACCESS Network at 705.688.0500. Individuals can also connect with Public Health at ext. 772 if seeking PEP .

Yes, Imvamune® is safe to receive. The vaccine is effective at protecting against mpox when given before exposure to the virus.

If you received another vaccination in the past 4 weeks, please let your health care provider know before getting Imvamune®.

There is currently limited information on the use of the vaccine in certain populations. If you are less than 18 years of age, pregnant, breastfeeding, immunocompromised or have atopic dermatitis, you should speak to your health care provider.

Your health care provider will review the risks and benefits of receiving the mpox vaccine.

Imvamune® is not indicated for the treatment of mpox infection. If you are experiencing any symptoms of mpox, please let your health care provider know before receiving the vaccine. Imvamune® should also not be given to individuals who have allergies to any of the ingredients in the vaccine.

If you have a history of myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the outer lining of the heart) linked to a previous dose of a first or second generation smallpox vaccine, speak to your health care provider.

Please talk to your health care provider about the potential risks of getting this vaccine.

No, Imvamune® will not leave a scar like previous smallpox vaccines as it is not given through scarification. Imvamune® is delivered through the subcutaneous route, which means that the needle is placed into the fatty tissue below the skin and above the muscle tissue.

Imvamune®, like other vaccines, may cause side effects, although not everyone will experience them. The most reported side effects are pain, redness, or swelling at the injection site. Other common side effects may include fatigue, headache, muscle aches and pain and nausea. These side effects are typically mild to moderate and on average did not last longer than 7 days after receiving the vaccine.

No cases of myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the outer lining of the heart) have been identified in clinical trials of Imvamune®. If you develop any cardiac symptoms after receiving the vaccine, please contact your health care provider.

Call your health care provider or go to the nearest emergency department if you experience any of the following symptoms after receiving the mpox vaccine:

• hives
• swelling of the face or mouth
• trouble breathing
• cardiac symptoms such as chest pain, shortness of breath, or palpitations

For more information on mpox, please see resources below or talk to your health care provider.

• Ontario Ministry of Health
• Public Health Ontario
• Public Health Agency of Canada
• World Health Organization
• United States Centers for Disease Control