As someone who has recently received the smallpox vaccine, you should know about new developments involving smallpox vaccination and heart problems. There is evidence that suggests that smallpox vaccination may cause cases of heart inflammation (myocarditis), inflammation of the membrane covering the heart (pericarditis), and a combination of these two problems (myopericarditis). A few cases of heart pain (angina) and heart attack also have been reported following smallpox vaccination. It is not known at this time if smallpox vaccination causes angina or heart attacks.
Careful monitoring of smallpox vaccinations given over recent months has suggested that the vaccine may cause myocarditis, pericarditis, and/or myopericarditis. Experts are exploring this more in depth.
Among the large number of people (military personnel and civilians) who have recently received the smallpox vaccine, a few cases of myocarditis and/or pericarditis have been identified:
Two cases of angina (chest pain caused by lack of blood flow to the heart) and three cases of heart attack have been reported among the 25,645 civilians recently vaccinated. Two of the persons with heart attacks have died. Four of these five patients, including the three persons with heart attacks, had clearly defined risk factors for coronary artery disease known in their medical history. The five patients had illness onset from 4 to 17 days after vaccination. It is not known at this time if smallpox vaccination caused these problems or if they occurred by chance alone (heart problems are very common). Reported events are not necessarily caused by the vaccine, and some or all of these events might be coincidental. Experts are investigating this question.
As someone who has received the smallpox vaccine, you should see a health care provider right away if you develop chest pain, shortness of breath or other symptoms of cardiac disease.
If you have been diagnosed by a doctor as having heart disease or risk factors for heart disease, and have concerns, contact your heart disease specialist or your regular health care provider. All people with heart disease or risk factors should receive the routine care recommended for persons with these conditions.