Myopericarditis is potential adverse reaction to smallpox vaccination.

2003 AUG 6 - (NewsRx.com & NewsRx.net) -- by Maria G. Essig, MS, ELS, senior medical writer - Clinicians involved in smallpox vaccination programs should be aware of myopericarditis as a potential adverse reaction, according to a report in the Journal of the American Medical Association.

"In the United States, the annual incidence of myocarditis is estimated at 1 to 10 per 100,000 population," stated Jeffrey S. Halsell at the University of Virginia and fellow members of the U.S. Department of Defense Smallpox Vaccination Clinical Evaluation Team. "As many as 1% to 5% of patients with acute viral infections involve the myocardium. Although many viruses have been reported to cause myopericarditis, it has been a rare or unrecognized event after vaccination with the currently used strain of vaccinia virus (New York City Board of Health)."

The investigators examined reports of adverse reactions to smallpox vaccination that were conveyed through the Defense Medical Surveillance System or the Vaccine Adverse Event Reporting System from mid-December 2002 to March 14, 2003.

Myopericarditis occurred in 18 out of 230,734 people vaccinated against smallpox, all of whom were white males, 21 to 33 years old, who developed symptoms 7 to 19 days (mean 10.5 days) after immunization.

"No cases of myopericarditis following smallpox vaccination were reported among 95,622 vaccinees who were previously vaccinated," said Halsell and his collaborators (Myopericarditis following smallpox vaccination among vaccinia-naive US military personnel. JAMA, 2003;289(24):3283-3289).

The similarity in the ...