A study published this week in the Journal of the American Medical Association (JAMA) has found that the risk of myocarditis (heart inflammation) after receiving an mRNA Covid vaccine (Pfizer or Moderna) was dramatically increased across many age groups and was highest after the second vaccination dose in young men.
The study found myocarditis reports were highest after the second vaccination dose in males aged 12 to 15 years at 70.7 per million Pfizer doses, compared to an expected rate of 0.53 per million, amounting to a 133-fold increase; in males aged 16 to 17 years at 105.9 per million Pfizer doses, compared to an expected rate of 1.34 per million, amounting to a 79-fold increase; and in young men aged 18 to 24 years at 52.4 per million Pfizer doses and 56.3 per million Moderna doses, compared to an expected rate of 1.76 per million, amounting to a 30-fold and 32-fold increase respectively. The full results are shown in the table below and a selection are depicted in the chart above.
The study comprised a review of reports of myocarditis to the U.S. Vaccine Adverse Event Reporting System (VAERS) that occurred after mRNA Covid vaccination between December 2020 and August 2021 in people over 12 years old. The researchers adjudicated and summarised the reports and compared the rates to expected rates of myocarditis using 2017-2019 data. For those under 30 they conducted medical record reviews and clinician interviews to investigate clinical presentation, test results, treatment, and early outcomes.
They found that out of 192,405,448 individuals receiving a total of 354,100,845 mRNA-based COVID-19 vaccine doses during the study period, there were 1,991 reports of myocarditis to VAERS, of which 1,626 met their case definition of myocarditis. Among the 1,626 cases, the median age was 21 years and the median time to symptom onset was two days. Males comprised 82% of the myocarditis cases for whom sex was reported, and where timing was reported, 82% occurred after the second vaccination dose.
The charts showing myocarditis cases by age and symptom onset are shown below.
Regarding deaths, the researchers write:
Among persons younger than 30 years of age, there were no confirmed cases of myocarditis in those who died after mRNA-based COVID-19 vaccination without another identifiable cause and there was one probable case of myocarditis [in those who died] but there was insufficient information available for a thorough investigation. At the time of data review, there were two reports of death in persons younger than 30 years of age with potential myocarditis that remain under investigation and are not included in the case counts.
The authors note that a difference between vaccine-related myocarditis and virus-related myocarditis was that the former comes on more quickly; they also note that it appears to be milder:
The onset of myocarditis symptoms after exposure to a potential immunological trigger was shorter for COVID-19 vaccine-associated cases of myocarditis than is typical for myocarditis cases diagnosed after a viral illness. Cases of myocarditis reported after COVID-19 vaccination were typically diagnosed within days of vaccination, whereas cases of typical viral myocarditis can often have indolent courses with symptoms sometimes present for weeks to months after a trigger if the cause is ever identified.
The major presenting symptoms appeared to resolve faster in cases of myocarditis after COVID-19 vaccination than in typical viral cases of myocarditis. Even though almost all individuals with cases of myocarditis were hospitalised and clinically monitored, they typically experienced symptomatic recovery after receiving only pain management. In contrast, typical viral cases of myocarditis can have a more variable clinical course. For example, up to 6% of typical viral myocarditis cases in adolescents require a heart transplant or result in mortality.
To what extent are these differences a reporting artefact, where adverse event reports are only made when a reaction occurs within days of a vaccination, but otherwise the link is unnoticed or dismissed?
The authors note that underreporting is likely, “given the high verification rate of reports of myocarditis to VAERS after mRNA-based COVID-19 vaccination”, and therefore “the actual rates of myocarditis per million doses of vaccine are likely higher than estimated”.
Another recent study found post-vaccination myocarditis adverse events were underestimated by the VAERS definition.
A third recent study, from Oxford University, found that myocarditis risk following Covid vaccination was up to 14 times higher than that following COVID-19 infection. It has been suggested that that study underestimated the risk following vaccination. It should also be noted that since vaccination provides little protection against infection the idea that the risk following vaccination is instead of and not as well as the risk following infection is not sound.
Myocarditis is not the only serious side-effect of these vaccines, and the vaccines do not protect well against infection or transmission. This means it is increasingly clear that the current Pfizer and Moderna Covid vaccines do not have the efficacy and safety profile that would make giving them to children and young people worthwhile or ethical.