DEVASTATING BREAKING study: "Karlstad et al. SARS-CoV-2 Vaccination & Myocarditis in Nordic Cohort Study of 23 Million Residents"; 1st & 2nd doses mRNA vax associated with increased myocarditis/pericarditis

by Paul Alexander

In a cohort study of 23.1 million residents across 4 Nordic countries, risk of myocarditis after the first & second doses of SARS-CoV-2 mRNA vaccines was highest in young males aged 16 to 24 years age

“Both first and second doses of mRNA vaccines were associated with increased risk of myocarditis and pericarditis.”


SARS-CoV-2 Vaccination and Myocarditis in a Nordic Cohort Study of 23 Million Residents

Brief overview for your perusal:

Researchers sought to examine the risks of myocarditis and pericarditis after SARS-CoV-2 injection/vaccination.

Researchers conduced 4 cohort studies and analyzed via meta-analysis. There were 23, 122, 522 residents who were 12 years or older (followed up from December 27, 2020, until incident myocarditis or pericarditis, censoring, or study end (October 5, 2021) (nationwide health registers in Denmark, Finland, Norway, and Sweden). Researchers assessed the 28-day risk periods following administration date of the 1st and 2nd doses of a SARS-CoV-2 vaccine, including BNT162b2, mRNA-1273, and AZD1222, also combinations. Measures were hospital admission for myocarditis or pericarditis.

Researchers reported that ‘among 23, 122, 522 Nordic residents (81% vaccinated by study end; 50.2% female), 1077 incident myocarditis events and 1149 incident pericarditis events were identified. 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, with adjusted IRRs of 1.75 (95% CI, 1.43-2.14) for BNT162b2 and 6.57 (95% CI, 4.64-9.28) for mRNA-1273. Among males 16 to 24 years of age, adjusted IRRs were 5.31 (95% CI, 3.68-7.68) for a second dose of BNT162b2 and 13.83 (95% CI, 8.08-23.68) for a second dose of mRNA-1273, and numbers of excess events were 5.55 (95% CI, 3.70-7.39) events per 100 000 vaccinees after the second dose of BNT162b2 and 18.39 (9.05-27.72) events per 100 000 vaccinees after the second dose of mRNA-1273. Estimates for pericarditis were similar.’

Researchers concluded that the 1st and 2nd doses of mRNA vaccines were related to elevated risk of myocarditis and pericarditis.

The association was clear. ‘For individuals receiving 2 doses of the same vaccine, risk of myocarditis was highest among young males (aged 16-24 years) after the second dose.’ These findings urge the balancing of benefits versus risks of these injections given the emerging myocarditis and pericarditis risks (that have been reported elsewhere and stably since inception of these injections).