Yellow fever vaccine seroconversion in travelers.

To assess immunity after yellow fever (YF) 17D live-attenuated vaccination, we measured the antibody levels before vaccination and at 21 days and 8 months after vaccination in YF-naïve travelers. Thirty subjects were enrolled in the study, with 100% providing sera at 21 days and 86.6% providing sera at 8 months. All subjects seroconverted by day 21, and the geometric mean titers of the anti-YF antibodies decreased between day 21 and month 8 from 6,451 to 1,246. This study corroborates the high rates of seroconversion achieved by the live-attenuated YF vaccine.