The U.S. Food and Drug Administration is adding a warning for the Pfizer and Moderna COVID-19 vaccines due to rare types of heart inflammation.The conditions, myocarditis and pericarditis, are inflammation of the heart muscle that is commonly caused by viruses.Since April, the U.S. Centers for Disease Control and Prevention says more than 1,000 people in the country developed those conditions after they were given an mRNA COVID-19 vaccine.”This is very rare. When you look at the overall likelihood, it’s probably in the range of 1 in 85,000 or so,” said Dr. Todd Ellerin, director of the division of infectious diseases at South Shore Health in Weymouth.Most cases of the conditions were found in men aged 16 to 30, particularly those 16 and 19 years old. The symptoms of myocarditis and pericarditis include chest pain, shortness of breath and palpitations (heart pounding), and those symptoms came on typically within days after the patients received the second dose of the Pfizer or Moderna vaccine.Some patients have been hospitalized, but those that recover quickly and their cases are considered mild. Ellerin says most of those patients recover from those conditions with no lasting heart damage.”The benefits of COVID-19 vaccination far outweigh the rare risk of vaccine-induced myocarditis,” Ellerin said.These issues are not associated with the Johnson & Johnson (Janssen) COVID-19 vaccine because it is not an mRNA vaccine.