A higher than usual number of cases of one type of heart inflammation have been reported following vaccination against Covid-19, particularly in young men after their second dose of an mRNA vaccine, the Centers for Disease Control and Prevention said Thursday.
A total of 226 cases of myocarditis or pericarditis after vaccination in people under the age of 30 have been confirmed, said Dr Tom Shimabukuro, deputy director of the CDC’s Office of Immunization Safety, in a presentation at a Food and Drug Administration advisory group. Further investigation is needed, however, to confirm whether the vaccination was the cause of the heart problem.
Normally, less than 100 cases would be expected for this age group.
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Adolescents and people in their early 20s made up more than half of the cases of myocarditis reported to CDC security surveillance systems after the Covid-19 vaccination, although they represent a fraction of the people who received vaccines.
“We clearly have an imbalance there,” Shimabukuro said.
The vast majority of cases were sent home after a visit to a hospital at the end of May. It is not known how many patients were admitted to hospital or, for example, were discharged following an emergency room visit. Fifteen patients remain hospitalized, including three in intensive care. Two of the ICU patients had other health problems.
The CDC had information on patient recovery in 220 cases; in over 80 percent of these cases, the patients got better on their own.
Following the presentation, Dr Cody Meissner, chief of pediatric infectious diseases at Tufts Children’s Hospital in Boston, said “it is difficult to deny that there is an event that appears to be happening in terms of myocarditis” .
Myocarditis is a condition that involves inflammation of the heart muscle. Symptoms can include fever and fatigue, as well as shortness of breath and a very specific type of chest pain. Patients tend to say that their chest hurts more when they lean forward. The pain tends to subside when they lean back.
If needed, treatment may involve anti-inflammatory drugs, such as ibuprofen, and in some cases, an intravenous drug called IVIg.
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Typically, children with myocarditis will be followed by a cardiologist for about six months to make sure there are no other significant problems. Most cases are usually mild and go away on their own.
Vaccine safety experts are always on the lookout for a range of possible side effects from any new vaccine. Despite the increase in the number of reported cases of myocarditis in young people, Shimabukuro said, no major red flags have been identified.
Nonetheless, the above-normal incidence deserves further consideration. The CDC will hold a meeting of its Advisory Committee on Immunization Practices on June 18 to further review the evidence and assess the risk of myocarditis after vaccination.
Until definitive links are made, health officials overwhelmingly recommend vaccination against Covid-19 for anyone aged 12 and over.
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