Smallpox shots tied to heart risk
Inoculated GIs face far higher potential for cardiac problems, report finds
By Judith Graham
Tribune staff reporter
Published May 14, 2004
Military personnel inoculated against smallpox face a seven to eight times greater risk of heart inflammation, according to a soon-to-be published report.
The study, by Walter Reed Army Medical Center researcher Dr. Dimitri Cassimatis, adds to the growing body of evidence that heart problems are a serious potential complication of the smallpox vaccine.
Preliminary results were disclosed Thursday at an American Medical Association briefing in New York City.
The study found a risk of myopericarditis, or heart inflammation, of 16 in 100,000 among military personnel who got smallpox vaccines for the first time, compared with a risk of 2 in 100,000 among personnel who had never been vaccinated. Inflammation caused such symptoms as chest pain, palpitations and lightheadedness.
"We know the vaccine turns on the immune system, and we think that in some people, it gets turned on against some heart cells," Cassimatis said.
The findings are significant because of the potential for mass inoculations of citizens against smallpox in case of a suspected bioterrorism attack.
Should a mass vaccination program be undertaken, "there is the potential for thousands of cases of cardiac complications," said Cassimatis, a cardiologist at Walter Reed. Most people should recover completely with proper diagnosis and treatment, including anti-inflammatory drugs, he said.
So far, results show that most heart inflammation associated with the smallpox vaccine occurs 7 to 14 days after inoculations and resolves naturally after two to three weeks without long-term consequences.
Since the Defense Department's smallpox vaccination program resumed in 2002, 615,000 American military personnel have gotten inoculations, and there have been 77 confirmed or suspected cases of heart inflammation.
The new data advance findings from a June study in the Journal of the American Medical Association, which found higher-than-expected rates of heart problems among 230,734 military personnel who had gotten smallpox inoculations for the first time. At that time, 18 cases of cardiac inflammation were reported.
Data from the Centers for Disease Control and Prevention show a similar trend. In a review of nearly 39,000 health workers vaccinated against smallpox over the last several years, the CDC uncovered 31 cases of cardiac complications, according to data presented earlier this year at the Infectious Diseases Society of America.
The CDC now recommends against giving the smallpox vaccine to anyone with a history of heart inflammation, coronary artery disease, or two risk factors for heart disease, including high blood pressure, diabetes, high cholesterol, old age and heart disease in the family.
Questions about the safety of the vaccine first came to light last year, when three people died of heart attacks after inoculations.
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