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Disclosures: Fink, Lee, Oster, Shimabukuro and Wallace report no relevant financial disclosures.
June 23, 2021
3 min read

CDC: Benefits of COVID-19 messenger RNA vaccines outweigh myocarditis risks



Disclosures: Fink, Lee, Oster, Shimabukuro and Wallace report no relevant financial disclosures.
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The CDC’s Advisory Committee on Immunization Practices on Wednesday agreed with CDC staff recommendations that myocarditis risks in young people associated with messenger RNA-based COVID-19 vaccines did not outweigh the vaccines’ benefits.

However, panel members agreed that the risks should be disclosed to patients, and an FDA official said the agency will be adding a warning about the risk to the labeling of the vaccines made by Moderna and Pfizer-BioNTech.

Source: Adobe Stock

“The direct benefit-risk assessment shows positive balance [of vaccination] for all age and sex groups,” Megan Wallace, DrPH, epidemic intelligence service officer at the CDC, said during a presentation.

“I clearly think that the presentation [CDC staff has] given today shows a benefit-risk balance in favor of benefit, and I feel very comfortable with that decision,” Jose R. Romero, MD, FAAP, chair of the Advisory Committee on Immunization Practices (ACIP), Arkansas secretary of health, director of the Arkansas Department of Health and professor of pediatrics and pediatric infectious diseases at University of Arkansas for Medical Sciences, said during a discussion. “The way it is presented will serve me as a clinician in explaining to parents that have some hesitancy regarding this.”

As Healio previously reported, ACIP’s COVID-19 Vaccine Safety Technical (VaST) Work Group in May reviewed “relatively few reports” of myocarditis in young recipients of messenger RNA (mRNA)-based COVID-19 vaccines.

As of June 11, there were 1,226 reports to the Vaccine Adverse Event Reporting System of myocarditis or pericarditis out of 300 million U.S. vaccine doses, Tom Shimabukuro, MD, MPH, MBA, deputy director of the CDC’s Immunization Safety Office and member of the CDC’s COVID-19 Vaccine Task Force, said during a presentation.

He said the reports were more frequent in people younger than 50 years compared with adults aged 50 years or older, in male recipients compared with female recipients and after the second dose compared with after the first.

Chart-confirmed myocarditis cases from the Vaccine Safety Datalink were elevated at 7 days and at 21 days after vaccination in people aged 12 to 39 years, Shimabukuro said, but he noted that the incidence remains rare, with 4.7 cases per 1 million women and 32 cases per 1 million men after dose two.

Grace M. Lee, MD, MPH, associate chief medical officer for practice innovation at Lucile Packard Children’s Hospital, professor of pediatrics at Stanford University School, a member of ACIP and co-chair of VaST, said available data suggest there is a link between mRNA-based vaccination and myocarditis or pericarditis, and “clinical presentation of myocarditis cases following vaccination has been distinct, occurring most often within 1 week after dose two, with chest pain as the most common presentation.”

Pablo J. Sanchez, MD, member of ACIP and professor of pediatrics at The Ohio State University – Nationwide Children’s Hospital, said he agreed that the benefits of vaccination outweighed the myocarditis risks, but “we need to be very upfront in terms of mentioning this as a potential risk of COVID messenger RNA vaccination. Hopefully, the parents and patients are aware of this before vaccination.”

Doran Fink, MD, PhD, clinical deputy director of the Division of Vaccines and Related Products Applications of the FDA’s Office of Vaccines Research and Review
, the FDA liaison to ACIP, said the FDA intends to add a warning about myocarditis risk to the labeling of the mRNA-based vaccines, but has not yet finalized the language.

In a case series of seven men (six who received an mRNA-based vaccine) aged 19 to 39 years and published in Circulation, researchers found that myocarditis in recently vaccinated young individuals could be treated effectively, as Healio previously reported.

According to the publication, treatments varied and included beta-blockers and anti-inflammatory agents, and all patients had their symptoms resolved by hospital discharge. The mean hospital length of stay was 3 days.

Other case series that have been published had similar findings, Matthew Oster, MD, MPH, pediatric cardiologist at Children’s Healthcare of Atlanta, medical officer at the CDC’s National Center on Birth Defects and Developmental Disabilities and member of the ACIP COVID-19 vaccines work group, said during a presentation.

“The mRNA vaccines may be a new trigger” for myocarditis, he said. “So far, we have seen benign clinical findings, but long-term data are needed.”

At the end of the meeting, HHS, the CDC, the American Academy of Pediatrics, the American Heart Association and other organizations released a statement that concern about myocarditis should not prevent people from getting vaccinated.

“The facts are clear: This is an extremely rare side effect, and only an exceedingly small number of people will experience it after vaccination,” the organizations stated. “Importantly, for the young people who do, most cases are mild, and individuals recover often on their own or with minimal treatment. In addition, we know that myocarditis and pericarditis are much more common if you get COVID-19, and the risks to the heart from COVID-19 infection can be more severe. The vaccines are safe and effective, and they prevent COVID-19 illness. They will help protect you and your family and keep your community safe. We strongly encourage everyone age 12 and older who are eligible to receive the vaccine under emergency use authorization to get vaccinated, as the benefits of vaccination far outweigh any harm.”