Imvamune Vaccine FAQs

Imvamune vaccine is approved in Canada for protection against smallpox, MPox (previously known as monkeypox), and other orthopoxvirus-related illnesses.

• It is a live vaccine, but it contains weakened virus and cannot make you sick.
• The vaccine is free and available to all eligible people. No ID or OHIP required.
• Two doses of Imvamune at least 28 days apart are recommended unless supply is low.
• Imvamune cannot be used to treat MPox.

Who should get the MPox vaccine?

• The vaccine can be used for protection for people who are at high risk of exposure to the MPox virus before getting exposed (Pre-Exposure Prophylaxis – PrEP)
• The following groups are now eligible for Imvamune:
  1. Individuals who engage in sex work or are planning to
  2. Two-spirited, non-binary, trans- or cis-gender individuals who self-identify or have sexual partners who self-identify as belonging to the gay, bisexual and other men who have sex with men (gbMSM) community AND have had at least one of the following:
     • a sexually transmitted infection (STI) within the last year, such as chlamydia, gonorrhea, or syphilis
     • two or more sexual partners (or may be planning to) or in a relationship where a partner may have other sexual partners
     • attended a bathhouse, sex club or similar place for sexual contact recently or may be planning to, or who work/volunteer in these settings
     • anonymous/casual sex or may be planning to, including using online dating or hookup apps
     • sexual contact with an individual who engages in sex work
• The vaccine may also be used after a possible exposure / close contact with someone with MPox (Post-Exposure Prophylaxis – PEP).
  • The vaccine should ideally be given within four days of exposure but can be given up to 14 days after the last exposure.
• At this time, people who have or have had MPox are not eligible for the vaccine.

Is Imvamune vaccine safe and effective?

• Yes, Imvamune is safe to receive and provides effective protection against the MPox virus.
• If you received another vaccination in the past four weeks, let your health care provider know before getting Imvamune, but even if you have recently had another vaccine, do not delay getting Imvamune if you were exposed to monkeypox or are at high risk of exposure, as the benefits outweigh the risks.
• The National Advisory Committee on Immunization recommends that Imvamune may be offered to the following special groups if there is an exposure risk, after a risk / benefit discussion with your health care provider—if you are pregnant, breastfeeding, immunocompromised, have atopic dermatitis or are less than 18 years of age.

Who should not receive Imvamune vaccine?

• If you are experiencing any symptoms of MPox, it is important to isolate right away and contact a health care provider. The vaccine is not used to treat MPox.
• Wait to get vaccinated if you have any COVID-19 symptoms, such as a high fever, and/or you are required to self-isolate.
• Imvamune should not be given to individuals who have allergies to any of the ingredients in the vaccine including trometamol or benzonase. It has a bromobutyl rubber stopper.
• There are trace amounts of gentamicin, ciprofloxacin and egg products, but hypersensitive individuals can safely receive Imvamune and just need to stay 30 minutes for observation.
• 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 1st or 2nd generation smallpox vaccine, speak to your health care provider.

What are the common side effects of Imvamune?

• Some people may feel sore and swollen for a few days where the needle was given, have a slight fever or feel tired for a day or two.
• Other common side effects may include fatigue, headache, muscle aches/pain, and nausea.
• Tylenol or ibuprofen may be taken afterwards, as directed, to reduce discomfort or fever.
• Children under 19 years of age must not be given ASA, Aspirin® or salicylates.

What else do I need to know?

• After getting the vaccine, it takes two weeks to build protection. During these two weeks, consider reducing your number of close contacts, including sex partners.
• After getting the Imvamune vaccine, wait at least two weeks before getting another non-live vaccine (e.g. COVID-19, flu or meningococcal) and four weeks before getting another live vaccine (e.g. MMR).
• If you have already had an older generation live smallpox vaccine or Imvamune vaccine, you can be re-vaccinated; check on this ministry guidance document.

When should I seek medical attention after immunization?

• If you or your child experiences any unusual side effects, seek medical attention & notify us.
• Go to Emergency at a hospital right away or call 911 if you or your child has any of the following after immunization:
  • swelling of the face and neck
  • problems breathing or shortness of breath
  • hives and itchy, reddened skin
  • chest pain or a pounding heartbeat

Reference

• Imvamune product monograph
• MPox Vaccine Information Sheet Ministry of Health
• NACI Interim guidance for use of Imvamune in context of MPox
• Toronto Public Health Monkeypox

Your Record of Protection

After you receive any immunization, make sure your health care provider updates your personal immunization record. Keep it in a safe place. Please inform Hastings Prince Edward Public Health of any immunizations not received from us.

Imvamune vaccine for MPox printable fact sheet (pdf)