Beyond the Myocarditis Headlines: What the Data and Our Memory Say About COVID-19 Shots for Kids

COVID-19 Vaccination for kids and teenagers

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Recommendations for COVID-19 vaccine administration are becoming more restrictive. The fear of vaccine-related myocarditis is driving the withdrawal of recommendations. However, this fear stems from both a distortion of scientific data and the forgetting of pandemic history.
 
We must not develop monocular vision and focus solely on myocarditis when assessing the risks and benefits of childhood COVID-19 vaccination. Vaccines have also been shown to reduce the incidence of pediatric cases of long-COVID. And although post-vaccination myocarditis can occur, it is “generally mild with rare cases of left ventricular dysfunction, heart failure, and arrhythmias.”

Let’s also remember that cases of myocarditis were appearing in young male college athletes in the Summer of 2020. Four athletes (15%) were reported to have cardiac magnetic resonance (CMR) findings consistent with myocarditis, and 2 of these cases had mild symptoms. And, on September 8, 2020, an article in Infection Control Today^® raised the question of whether COVID-19 is not primarily a heart and vascular disease. All of this occurred before any COVID-19 vaccine was available.

During a recent Senate hearing, it was stated that the incidence of postvaccination myocarditis in children is 6 to 8 per 10,000. I feel many interpreted these statistics as applying to all children. However, this high rate may only apply to a subset of young post-pubescent males, but even in that group, the quoted incidence appears to be high. The American College of Cardiology determined the rate of myocarditis for males between the ages of 12 and 24 years to be 1.07 per 10,000.In a meta-analysis published in JAMA Pediatrics, Watanabe and colleagues reported that, among children aged 5 to 11 years, the rate of postvaccine myocarditis was 1.8 per million (0.018 per 10,000).

Unfortunately, misinformation regarding the rate of vaccination-induced myocarditis in relation to infections is rampant. I feel this is due in part to a report from Florida’s Surgeon General, Joseph Ladapo, MD, PhD. The Associated Press reported that his final report regarding cardiac-related deaths in young men is reported to have omitted information, which “showed that catching COVID-19 could increase the chances of a cardiac-related death much more than getting the vaccine.” The report was also based on a minimal number of deaths, 20, which allowed biases to easily alter the results.

Even in the highest-risk vaccination group, young postpubescent males, the data make a compelling argument that the rate of myocarditis from COVID-19 infections is higher than from vaccination.

Vinay Prasad, MD, MPH, the current FDA head of the Center for Biologics Evaluation and Research, stated in a manuscript he coauthored, "The incidence of myocarditis found for young men after SARS-CoV-2 infection is larger than what we found for myocarditis following COVID-19 vaccination." There were, however, a few caveats.In the paper, Benjamin Knudsen, MD, and Prasad stated that infection rates for vaccinations were found to be higher in individuals under the age of 40 after receiving the second dose of the Moderna COVID-19 Vaccine. It should also be noted that the data used in this analysis is from the Moderna Spikevax vaccine and has a higher dosage than Moderna’s mNEXSPIKE vaccine, which is available this year for those under the age of 65.

Most studies have found that the greatest risk of post-vaccination myocarditis is after the second dose of an mRNA vaccine. Faksova et al, reported the odds ratio (person-years of follow-up) of developing myocarditis after the second dose of an mRNA vaccine is 2.86 for the Pfizer vaccine and 6.10 for the Moderna (Spikevax) vaccine.The odds ratios are lower for the first, and third doses of the vaccine. For comparison, Zuin et al, reported a hazard ratio (risk) for patients (mean age of 56.1 years) developing myocarditis after infection of 5.16.

Based on a literature review, Knudsen and Prasad reported the risk of myocarditis in young males aged 12 to 19 years to have a range of 1/2562 to 1/9442.The authors also discussed the analysis by Patone et al, which found that when all ages are considered, the incidence of myocarditis after infection was at least 4 times larger than after vaccination with a first or second mRNA dose. For those under 40, the second dose of the Moderna (Spikevax) vaccine had a larger incidence of myocarditis than after infection. As stated above, Moderna is currently distributing a new vaccine for younger patients, mNEXSPIKE, which has a lower antigen dosage.

Drs Knudsen and Prasad also expressed concern about bias in studies examining the incidence of myocarditis after infection, as most studies rely on documented infections with a positive COVID-19 test, which may result in an undercount of cases.Although this may be true, I am not sure it would have a meaningful impact on rates or ratios.

An interesting question is whether, because the incidence of myocarditis is highest after the second dose of the vaccine, giving the first and second doses in early childhood would decrease the risk of myocarditis in young post-pubescent males.

The overall findings strongly support that COVID-19 vaccinations are safer than contracting an infection. The available data makes a compelling argument for everyone, not just those over the age of 65 or those with risk factors, but for all individuals aged 6 months and older to receive this year’s updated COVID-19 booster. This is of utmost importance in children where the first exposure to a virus should be in a vaccine and not an infection.