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

During January 24-April 13, 2003, smallpox vaccine was administered to 32,644 civilian health-care and public health workers in 54 jurisdictions as part of an effort to prepare the United States for a possible terrorist attack using smallpox virus. This report updates information on all vaccine-associated adverse events among civilians vaccinated since the beginning of the vaccination program and among contacts of vaccinees, received by CDC from the Vaccine Adverse Event Reporting System (VAERS) as of April 13.