This information was obtained from the Mayo Clinic Website.
No reference was made to any specific Study or Report but seemed to be based upon some general statistical data generated from standard Medical Records and standard reporting procedures.
In the U.S., there has been an increase in reported cases of myocarditis and pericarditis after mRNA COVID-19 vaccination, particularly in males ages 12 to 29. Myocarditis is the inflammation of the heart muscle, while pericarditis is the inflammation of the lining outside the heart. These reports are rare.
Of the cases reported, the problem happened more often after the second dose of the COVID-19 vaccine and typically within one week of COVID-19 vaccination. Most of the people who got care felt better after receiving medicine and resting. Research also shows that there’s an increased risk for these conditions after the Novavax COVID-19vaccine is given.
Symptoms to watch for include:
- Chest pain
- Shortness of breath
- Feelings of having a fast-beating, fluttering or pounding heart
If you or your child has any of these symptoms within a week of getting a COVID-19vaccine, seek medical care.
If you or your child develops myocarditis or pericarditis after a dose of an mRNA COVID-19 vaccine, the CDC recommends avoiding getting another dose of any COVID-19vaccine.
This article contains far more information and goes into some detail re studies and research (dated August 2021) thus was based upon some fairly early studies.
https://hms.harvard.edu/news/covid-19-vaccine-safety