The Centers for Disease Control and Prevention reported a higher-than-usual number of cases of a heart problem, particularly heart inflammation among younger men after their second dose of the mRNA vaccine.

Dr. Tom Shimabukuro, deputy director of the CDC's Immunization Safety Office, said young adults have reported a total of 226 cases of myocarditis or pericarditis after vaccination, according to an NBC News report.

Shimabukuro said the developments during a presentation to a Food and Drug Administration advisory group. However, more investigation is needed to confirm whether the vaccination was the cause of the heart problem among young adults.

Teenagers and young adults in their early 20s accounted for more than half of the myocarditis cases reported to the CDC's safety monitoring systems after their COVID vaccines.

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Heart Problem Among Teens and Young Adults

Dr. Elisabeth Albert, the co-author of the report on heart problem and its connection to the COVID vaccine, said that the data they have on the matter suggests a small risk of myocarditis, inflammation in and around the heart, as well as thrombosis-related myocardial infarction, according to UMass Medical School web site.

Dr. John Dickey, assistant professor of medicine, said that his colleagues have identified six additional cases of myocarditis, which were all in men between the ages of 17 and 35.

Dickey added that they became sick within four days of their second vaccine. He noted that their heart function was not significantly damaged.

Dr. Gerard Aurigemma said that it seems likely that the immune response to the infection or the vaccine plays a role.

Meanwhile, experts highlighted the possibly rare side effect of myocarditis as compared to the potential risk of COVID, including the persistent syndrome called "long COVID."

They also noted that acute COVID itself can cause myocarditis, according to The New York Times report.

Dr. Celine Gounder, an infectious disease specialist at Bellevue Hospital Center in New York, said that it may simply be a coincidence that some people are developing heart problems after getting their COVID vaccine.

One Oregon teen had recently reported some of the common side effects of the vaccine. However, he also mentioned to his mom that his heart hurt, according to an Oregon Live report.

The Oregon teen was brought to the hospital the next day and was put on anti-inflammatories and oxygen. He was diagnosed with myocarditis.

Some 6.4 million adolescents ages 12 to 17 in the United States have already received at least one dose of their COVID vaccine.

Aside from the United States, there have been cases reported from Israel and Canada of the heart inflammation condition after immunization.

Public health officials and specialists say it is not yet clear whether there is a causal link between the COVID vaccine and the heart problem.

Chest pain is unusual in pediatric patients. However, myocarditis can also be a side effect of other vaccinations, such as smallpox and influenza.

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WATCH: CDC investigating heart issues among some teens after COVID-19 vaccine l GMA - from ABC News