Update: adverse events following smallpox vaccination--United States, 2003.

During January 24-March 28, 2003, smallpox vaccine was administered to 29,584 civilian health-care and public health workers in 54 jurisdictions as part of an effort to prepare the United States for a terrorist attack using smallpox virus. This report summarizes data on ten cases of cardiac adverse events reported among civilian vaccinees since the beginning of the smallpox vaccination program, including three new cardiac adverse events reported to CDC from the Vaccine Adverse a fall Event Reporting System (VAERS) during March 24-30. Fourteen cases of myocarditis and one fatal myocardial infarction have been reported among military personnel. This report summarizes data on the three new cases of cardiac adverse events, updates data on seven previously reported cases among civilian vaccinees (Table 1), summarizes selected cases of cardiac adverse events among military vaccinees, and updates information on all adverse events reported in the civilian vaccination program as of March 30.