Because of the announcement of the ACIP recommendation on December 13, 2002 and the commencement of the smallpox vaccine program at various facilities nationally, adverse events data are being carefully analyzed by CDC researchers. As previously discussed, CDC recommend a cardiac risk profile be included in the pre-event vaccination screening criteria. A definitive link between the onset of myopericarditis and the smallpox vaccine is suspected, but under investigation. The CDC ascertains there is uncertain evidence of any association between ischemic heart disease and vaccinia (CDC, 2003c). As the pre-event vaccine program expands, occupational health professionals should be cognizant of changes to the smallpox vaccine recommendations and modify their policies and protocols appropriately.