Covid-19: Canada warns of ‘very rare risk’ of heart issues from mRNA vaccines

The NACI’s advisory effectively concerns two mRNA vaccines – the ones rolled out by Pfizer-BioNtech and Moderna – that have emergency-use authorisation in Canada

Canadian health authorities have issued a public advisory saying those taking mRNA Covid-19 vaccines should be warned of the “very rare risk” of heart inflammation caused by the shots.

Canada's Prime Minister Justin Trudeau receives his second Covid-19 vaccine at a pharmacy in Ottawa, Canada on July 2, 2021. (REUTERS)

The advisory effectively concerns two mRNA vaccines – the ones rolled out by Pfizer-BioNtech and Moderna – that have emergency-use authorisation in Canada.

The National Advisory Council on Immunisation (NACI) recommended on Friday that “informed consent” for those receiving mRNA vaccines should “include a discussion about the very rare risk” of the two conditions - myocarditis or pericarditis - following vaccination.

It stated that as a “precaution”, those who experience the two adverse reactions after receiving the first dose should “wait to get the second dose until more information is available”.

The NACI continued to strongly recommend that mRNA vaccines be offered to those who are eligible to receive it.

“We have been closely monitoring the evolving situation of rare cases of myocarditis or pericarditis following mRNA vaccination among younger people. The NACI is encouraged to see that the clinical presentations appear mild, and resolve quickly. The benefits of the Covid-19 immunisation programme continue to outweigh the relatively small risk for all people including adolescents,” NACI chief Shelley Deeks said.

Her views were echoed by Canada’s chief public health officer Theresa Tam, who said, “There have been a small number of cases of myocarditis and pericarditis reported in Canada after vaccination. Evidence is evolving, and Canadian and international investigations into an association between myocarditis or pericarditis and mRNA vaccines continue. I want to let Canadians know that the benefits of mRNA Covid-19 vaccines continue to outweigh their potential risks.”

According to data available from Health Canada till June 18, there were 65 cases of myocarditis or pericarditis detected in the country. Of these, 50 happened after Pfizer-BioNtech jabs, 10 after Moderna and five after Covishield, which is the India-made version of the Oxford-AstraZeneca vaccine.