MEMO: Mpox Vaccination        

TO:   Health Care Professionals in Niagara Region       

FROM: Vaccine Preventable Disease program, Niagara Region Public Health

REFERENCE: Mpox vaccination

DATE: August 28, 2024

On August 14, 2024, the World Health Organization declared the mpox outbreak in the Democratic Republic of the Congo, and a growing number of countries in Africa, a public health emergency of international concern (PHEIC). This is due to the emergence and spread of the more severe clade 1b strain of the virus, as well as outbreaks of other mpox clades. While Niagara has not had a confirmed case of mpox since 2022, the increased media coverage has likely resulted in questions from your patients. The purpose of this memo is to provide a reminder of the eligibility criteria for vaccination and an epidemiological summary of mpox cases.

Mpox Activity in Canada and Ontario

According to the August 14 Public Health Agency of Canada statement, there have been no cases of the more severe clade I mpox virus in Canada. There has been an ongoing outbreak of clade II mpox in Canada since 2022.

An increase in mpox activity (clade II) has been observed in Ontario since mid-January 2024 with a total of 142 confirmed cases occurring from January 1 to August 10, 2024. In comparison, only 33 confirmed cases were reported in 2023. 119 of the 142 cases were reported by Toronto Public Health, with the remaining 23 cases reported by 10 other public health units in Ontario.

Between January 1, 2024 and August 14, 2024, a total of 1,850 doses of Imvamune® vaccine have been administered in Ontario among 965 people.

Mpox Vaccine

Refer to the Ontario Ministry of Health’s Mpox Vaccine (Imvamune®) Guidance for Health Care Providers for the most up to date criteria for vaccine eligibility.

Niagara Region Public Health has offered Imvamune® since 2022. Eligible individuals can book an appointment at a general Public Health vaccination clinic for their first or second dose by calling Public Health at 905-688-8248 ext. 7425.

• The mpox vaccine is not available for the general public looking to get vaccinated for travel purposes. Niagara Region Public Health is asking residents to review the eligibility criteria for the mpox vaccine before calling to book an appointment.
• As per the Public Health Agency of Canada statement, vaccination is expected to protect against both clade I and II; however, two doses of Imvamune® are needed for best protection. Only 35.7% of individuals in Ontario have received their second dose.

Health Care Provider Action

• If your practice is already seeing patients who would benefit from receiving the mpox vaccine in your office
  • Advise them to call Public Health at 905-688-8248 ext. 7425 to make an appointment
  • There is a very limited supply of mpox vaccine. However, under extenuating circumstances, Public Health may be able to release a dose of Imavune® for you to administer. Call Public Health at 905-688-8248 or 1-888-505-6074 ext. 7396 to have this discussion.  
• Patients that have reported receiving their first dose of Imavune® more than 28 days ago do not need to restart the series. Recommend that these patients receive their second dose as soon as possible.

More Information

• Mpox | Public Health Ontario
• Public Health Ontario’s epidemiologic summary
• Call the Vaccine Preventable Disease program at 905-688-8248 or 1-888-505-6074 ext. 7396