Secondary and tertiary transfer of vaccinia virus among U.S. military personnel--United States and worldwide, 2002-2004.

In December 2002, the Department of Defense (DoD) began vaccinating military personnel as part of the pre-event vaccination program. Because vaccinia virus is present on the skin at the site of vaccination, it can spread to other parts of the body (i.e., autoinoculation) or to contacts of vaccinees (i.e., contact transfer). To prevent autoinoculation and contact transfer, DoD gave vaccinees printed information that focused on hand washing, covering the vaccination site, and limiting contact with infants (1,2). This report describes cases of contact transfer of vaccinia virus among vaccinated military personnel since December 2002; findings indicate that contact transfer of vaccinia virus is rare. Continued efforts are needed to educate vaccinees about the importance of proper vaccination-site care in preventing contact transmission, especially in household settings.