Several cases of severe adverse events associated with the yellow fever vaccination are detailed in the November 8th issue of the U.S Centers for Disease Control and Prevention's (CDC) Morbidity and Mortality Report. According to the report, between May 2001 and October 2002, the CDC received reports of six cases of serious neurologic (4) and systemic (2) adverse events associated with the vaccination. All six individuals were reportedly vaccinated in the United States and required hospitalization.

The CDC is recommending that clinicians report to the Vaccine Adverse Event Reporting System patients with fever (>24 hours) or systemic illness within 30 days following vaccination. A spokesperson for the CDC said the cases emphasize the need for further surveillance of the yellow fever vaccine and its related disorders.