The Centers for Disease Control and Prevention is reporting a higher-than-average incidence of heart inflammation among young men who have received second doses of the Pfizer and Moderna coronavirus vaccines. Since vaccinations began, 226 men under 30 have sought treatment for myocarditis or pericarditis; 15 of them remain hospitalized, with three in intensive care. More than 130 million Americans have received second doses of the preventatives. Dr. Tom Shimabukuro, deputy director of the CDC’s Immunization Safety Office, said during a Thursday presentation to a Food and Drug Administration group that further investigation was needed: “We clearly have an imbalance here.” The CDC will convene an “emergency meeting” on the topic June 18.