Toronto 
Ontario is recommending Pfizer over Moderna COVID-19 vaccine for those aged 18-24 years due to a rare heart condition.
The province says there was an observed increase in pericarditis and myocarditis cases in Ontario following vaccination with Moderna compared to Pfizer in the 18 to 24-year-old age group. The heart condition was particularly pronounced among males after the second dose.
As per the report by Public Health Ontario, the cases in males aged 18-24 years following the Pfizer-BioNTech vaccine as the second dose was 37.4 per million doses, while it was 263.2 per million following the Moderna vaccine as the second dose.
There were a total of 204 reports that met the Brighton Collaboration case definition levels of diagnostic certainty 1, 2 or 3 for myocarditis or pericarditis in the province from December 13, 2020 to August 7, 2021. Among the 204 reports, 79.9% occurred in males and 69.6% occurred following the second dose.
According to the news release, the majority of reported cases have been mild with those affected recovering quickly, normally with anti-inflammatory medication.
Issuing the guidance, Ontario Chief Medical Officer of Health Dr. Kieran Moore said, “Out of an abundance of caution, Ontario is issuing a preferential recommendation of the use of Pfizer-BioNTech vaccine for individuals aged 18-24 years old effective immediately based on the current available analysis from Ontario’s adverse events following immunization (AEFI) surveillance system.”
Ontario will continue to offer Moderna vaccine to those who wish to receive this brand of vaccine with informed consent.
The province is reminding Ontarians that vaccination is the best way to protect against COVID-19 related complications, and the risk of contracting myocarditis and other serious adverse events including pericarditis, arrhythmia, deep-vein thrombosis, pulmonary embolism, myocardial infarction, intracranial hemorrhage and thrombocytopenia is 18 times higher among patients with COVID-19.
