Canada’s Chief Public Health Officer says smallpox vaccine can work on monkeypox 

Fewer than a couple of dozen suspected Canadian cases of monkeypox are currently being investigated at the national microbiology laboratory. 

Chief Public Health Officer Dr. Theresa Tam says the cases are mainly in Quebec with a couple of contacts being followed up in British Columbia as well. “We understand from other countries that are reporting cases that the current monkeypox strain, or clade, is the West African clade. We have not yet confirmed that in Canada,” she says.

However, Tam says two cases are confirmed in Canada. With the samples being processed at the national microbiology lab today (Friday), Tam says we could see more confirmations in the coming hours and days.

The World Health Organization says monkeypox has so far been reported in 11 countries that normally don’t have the disease. WHO officials say as of Friday, there are about 80 confirmed cases and 50 pending investigations. Tam says the extent of the spread of monkeypox in Canada is currently unknown, but officials do know that the virus is generally spread through close contact. 

Tam says the vaccines currently being investigated by Health Canada for monkeypox were originally developed for smallpox which was declared eradicated by the WHO in 1980. 

“One of the vaccines seems to have an effect on monkeypox as well. So there hasn’t essentially been a clinical trial of the vaccines against monkeypox itself but I think based on what we know globally the smallpox vaccines can be applied to monkeypox. In particular, there is one that has monkeypox included in its labeling.”

Tam says Health Canada is having discussions internationally but also with provincial counterparts around potential use. She says the country has a limited supply of the smallpox vaccine but was not able to disclose the exact number based on security reasons.

1/4 A lot of comments re: #monkeypox (MPX) doesn’t spread efficiently. While this event is serious and vigilance is essential, monkeypox is considered to have limited spread compared to other viruses (e.g. COVID-19, influenza, measles, etc.) https://t.co/Obv9uTv4L6

— Dr. Theresa Tam (@CPHO_Canada) May 20, 2022

***With files from Mo Fahim