MPOX virus (formerly known as monkeypox) is a viral illness that is usually spread from animals to humans. Human-to-human transmission can occur through direct contact with MPOX sores, bodily fluids, or respiratory droplets, or through contact with contaminated clothing, bedding, or common items. 


Symptoms of MPOX typically include a fever, headache, swollen lymph nodes and exhaustion, followed by the development of a rash over a person's body.


  • If you have had or think you have had a MPOX exposure, call 1-888-221-2133 during regular business hours (8:30 AM - 4:30 PM | Monday to Friday).
  • After hours and on weekends, please call our on-call service: 1-800-431-2054

Vaccine and eligibility

Based on the Ontario Ministry of Health guidelines, the MPOX vaccine, Imvamune®, should be considered for the following:

  • Pre-exposure vaccination: when Imvamune® is administered before known exposure to the virus
  • Post-exposure vaccination – when Imvamune® is administered for individuals who have had a high-risk exposure to a probable or confirmed case of MPOX, or within a setting where transmission is happening

NOTE: Individuals with signs or symptoms of MPOX infection should NOT receive the vaccine as the vaccine is not indicated in the treatment of MPOX infection.

Imvamune® is available to these groups if they meet one of the following eligibility criteria:

For the purpose of pre-exposure prophylaxis (PrEP):

a) Two-spirited, non-binary, trans, cis-gender, intersex or gender-queer individuals who self-identify or have sexual partners who self-identify as belonging to the gay, bisexual, pansexual and other men who have sex with men (gbMSM) community, AND at least one of the following:

  • Have or are planning to have two or more sexual partners or are in a relationship where at least one of the partners may have other sexual partners, OR
  • Have received a diagnosis of a bacterial sexually transmitted infection (STI) (e.g. chlamydia, gonorrhea, or syphilis) within the last year, OR
  • Have attended venues for sexual contact (i.e. bath houses, sex clubs) recently or may be planning to, or who work/volunteer in these settings, OR
  • Have had anonymous sex (i.e. using dating or hookup apps) recently, or may be planning to, OR
  • Are a sexual contact of an individual who engages in sex work

b) Individuals who self identify as engaging in sex work or may be planning to, regardless of self-identified sex or gender.

Household and/or sexual contacts of those identified for PrEP eligibility in parts (a) and (b) above AND who are moderately to severely immunocompromised or pregnant may be at higher risk for severe illness from a MPOX infection and may be considered for PrEP. Individuals should contact their healthcare provider (or their local public health unit) for more information. Also see relevant sections under Special Populations below for additional considerations.


  • Given the current epidemiology of MPOX in Ontario, Imvamune® should be offered as a two-dose primary series, with at least 28 days between first and second doses for individuals currently eligible for PrEP or Post-exposure vaccination. This approach will continue to be evaluated with any changes in the epidemiology and evidence surrounding the vaccine. 
  •  It is recommended to not receive Imvamune® at the same time as other vaccines, and to wait at least 14 days after receiving Imvamune before getting any other vaccinations.

Special Populations

Individuals with history of previous smallpox vaccine

Individuals eligible for Imvamune® as pre-exposure vaccination or post-exposure vaccination who previously received either an older generation replicating (live) smallpox vaccine or Imvamune® can be re-vaccinated:

  • For individuals with a history of receiving one dose of a live smallpox vaccine, a single dose of Imvamune® is recommended.
  • For individuals who completed a two-dose series of Imvamune® more than two years ago, a single booster dose of Imvamune® is recommended.
  • For individuals who completed a two-dose series of Imvamune® within the last two years, no further doses are recommended.

If you meet vaccine eligibility and/or want to talk about whether you meet eligibility, please call HPPH at 1-888-221-2133 ext 3558 or email our HPPH vaccine team. Messages using this form are seen by a public health nurse.