Late vaccination against yellow fever of travelers visiting endemic countries.

BACKGROUND

Guidelines issued by the WHO call for immunization against yellow fever (YF) at least 10 days before entering an endemic area. We assessed the extent at which travelers complied with these guidelines.

METHODS

A two-phase study at one travel center in Israel. Phase I-travelers planning to visit YF-endemic areas (n = 295) were evaluated in regard to the timing of administration of YF vaccine before travel. Phase II-the specific causes of arriving late were studied prospectively in another group of 132 travelers.

RESULTS

Phase I-one-half of the travelers (n = 148) headed to South America (SA), and 147 to Africa. The mean age (+/-SD) of this cohort was 30.9 (+/-14.9) years (range 6-75 years). Overall, 64 (21.7%; 95% confidence interval, 17.4-26.8) received the vaccine less then 10 days before departure. However, only 10.8% of those heading to SA arrived late, as compared to 32.7% of those heading to Africa (p < 0.0001). Phase II-a last minute's decision was the commonest reason given for arriving late (43.2%).

CONCLUSION

One-fifth of travelers fail to comply with the WHO guidelines concerning YF vaccination. Travelers and travel agents alike need to be reminded of the importance of timely vaccination against YF.