CDC reports heart problems in three more smallpox vaccinees

Apr 3, 2003 (CIDRAP News) – The Centers for Disease Control and Prevention (CDC) has reported three more cases of heart problems in recent smallpox shot recipients, including two cases of heart inflammation and one heart attack. The cases bring the number of civilians who experienced cardiac problems after vaccination to 10 since the immunization program began in January.

In addition, four new cases of heart inflammation (myocarditis and/or pericarditis) have been reported in military vaccinees in the past week, bringing the military total to 14. One of the new cases is in a 29-year-old man who was hospitalized with congestive heart failure but was improving, according to the CDC.

The new reports of heart inflammation "are consistent with previous reports describing a potential causal association between vaccination and myopericarditis," states the CDC report in the Apr 4 issue of Morbidity and Mortality Weekly Report. However, "Any association between smallpox vaccine and ischemic heart disease remains unclear," the report says.

Last week the CDC reported three myocardial infarctions (MIs) (two of them fatal), two cases of angina, and one case each of myocarditis and myopericarditis in recent civilian vaccinees. In addition, the Department of Defense last week reported 10 cases of myocarditis and pericarditis and one fatal MI in military personnel. The events prompted the CDC on Mar 25 to recommend against smallpox shots for people with known heart disease. Earlier this week, CDC expanded this to include people with three or more major cardiac risk factors.

The three people in the new civilian cases have all recovered, according to MMWR. Two of them, a previously vaccinated 56-year-old man and a 32-year-old woman with no previous smallpox shot, were found to have myopericarditis. Their symptoms lasted about a week. The other person, a 64-year-old man with a history of exertional dyspnea and eight previous smallpox shots, experienced chest discomfort and dizziness 2 days after his vaccination. After an MI diagnosis and placement of coronary artery stents, he returned to work.

The congestive heart failure case occurred in a 29-year-old military man, according to the report. He had onset of an influenza-like illness a few days after his vaccination and later experienced dyspnea while lying down. He was hospitalized 20 days after vaccination. After getting a diagnosis of myopericarditis, he was treated for pulmonary edema. Polymerase chain reactions tests of myocardial tissue were negative for vaccinia and several other viruses. The man remained hospitalized yesterday but was stable and improving, the report said.

The man's case shows the potential severity of myopericarditis, "which can lead to severe cardiac dysfunction or dysrhythmia," the report states. It says that a few fatal cases of myocarditis after smallpox vaccination have been reported in Europe and Australia.

Preliminary autopsy findings for the three people—two civilians and one solider—who died of MI within days or weeks after smallpox vaccination included no evidence of disseminated vaccinia infection or myocarditis, the CDC reported. "These findings suggest the ischemic events in these patients did not result from vaccinia-associated myocarditis," but it is not known whether smallpox vaccination could contribute to the events in some other way, the report says.

CDC said that with 29,584 civilians vaccinated so far, there have been no reported cases of several potentially life-threatening complications historically associated with the vaccine: progressive vaccinia, eczema vaccinatum, postvaccinial encephalitis, and encephalomyelitis. Further, no cases of vaccinia transmission from civilian vaccinees to others have been reported. The vaccinees include 18,344 healthcare workers, about a third of whom have been followed for more than a month, the report says.

CDC. Update: adverse events following smallpox vaccination—United States, 2003. MMWR 2003;52(13):278-82 [Full text]

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