A peer reviewed study of over 23 million people in the Nordic countries of Denmark, Finland, Norway, and Sweden, has been published in JAMA (Journal of the American Medical Association). They identified 1,077 “incident myocarditis events” and 1,149 “incident pericarditis events” among 23,122,522 Nordic residents (81% of whom were vaccinated by the end of the study; 50.2% of whom were female). “Within the 28-day period, for males and females 12 years or older combined who received a homologous schedule, the second dose was associated with higher risk of myocarditis.”
“This cohort study of 23.1 million residents across 4 Nordic countries showed higher rates of myocarditis and pericarditis within 28 days after being vaccinated with SARS-CoV-2 mRNA vaccines compared with being unvaccinated,” the study says. “The risks of myocarditis and pericarditis were highest within the first 7 days of being vaccinated, were increased for all combinations of mRNA vaccines, and were more pronounced after the second dose. A second dose of mRNA-1273 had the highest risk of myocarditis and pericarditis, with young males aged 16 to 24 years having the highest risk.”