TORONTO — An increase in cases of a rare heart condition in young adults who received the COVID-19 Moderna vaccines has prompted Ontario to recommend the Pfizer-BioNTech shots for those aged 18 to 24.
Ministry of Health officials made the recommendation on Wednesday, noting that the rise of myocarditis and pericarditis cases has been particularly observed among males in that age group.
Between June and August, the province said the risk of myocarditis and pericarditis for males aged 18 to 24 following a second dose of Moderna was one in 5,000.
For those who received the Pfizer-BioNTech shot, the rate was one in 28,000.
That data was based on 96,000 second doses of vaccines administered to men in that age group.
The province said Wednesday that the side-effect is still considered rare and the majority of cases are mild.
Most cases occur within the first week after receiving a second dose of vaccine and are treated with anti-inflammatory medication.
Officials said Wednesday that no deaths have been associated the condition and fewer than 10 people have been admitted to intensive care with it.
Almost all cases have been diagnosed in emergency rooms and many are hospitalized, officials said, but hospital stays are typically short.
Symptoms include chest pain, shortness of breath, irregular heartbeat, fatigue or general malaise.
The province's recommendation takes effect immediately but people can still take Moderna vaccines if they choose to, with informed consent.
This report by The Canadian Press was first published Sept. 29, 2021.
The Canadian Press
