Yellow fever vaccine: An updated assessment of advanced age as a risk factor for serious adverse events

Since 1996, the scientific community has become aware of 14 reports of yellow fever vaccine (YEL)-associated viscerotropic disease (YEL-AVD) cases and four reports of YEL-associated neurotropic disease (YEL-AND) worldwide, changing our understanding of the risks of the vaccine. Based on 722 adverse event reports after YEL submitted to the U.S. Vaccine Adverse Event Reporting System in 1990–2002, we updated the estimates of the age-adjusted reporting rates of serious adverse events, YEL-AVD and YEL-AND. We found that the reporting rates of serious adverse events were significantly higher among vaccinees aged ≥60 years than among those 19–29 years of age (reporting rate ratio = 5.9, 95% CI 1.6–22.2). Yellow fever is a serious and potentially fatal disease. For elderly travelers, the risk for severe illness and death due to yellow fever infection should be balanced against the risk of a serious adverse event due to YEL.