The Department of Defense reported its first case of inflammation in or around the heart (myopericarditis) after smallpox vaccination in early February 2003. As of January 2008, DoD has identified 161 cases of acute myocarditis and/or pericarditis among 1.4M smallpox vaccinees, with symptoms appearing 7 to 19 days after vaccination. These people had clinical conditions that varied from mild to moderate; the condition was severe in two cases.
Most cases occurred among those receiving smallpox vaccinations for the first time. Most cases occurred among men.
The health of our people is foremost in our priorities. These cases were followed carefully to evaluate their recovery, at 27 hospitals in 21 states and several countries overseas. Detailed follow-up cardiac testing is available in 46 cases: all had normal electrocardiograms (EKGs), echocardiograms ("echos") and normal treadmill test results. Based on our data and European experience, we have reason to believe these people should recover and remain well.