http://www.medscape.com/viewarticle/425277_6
Infectious Diseases, February 2002 Journal Scan
From
Emerging Infectious Diseases
11/01/2001 (Volume 7, Number 6)
Martin
M, Weld LH, Tsai TF, et al.
Emerging Infectious Diseases. 2001;7(6):945-951
Yellow
fever (YF) is a serious illness still endemic in some tropical areas of South
America and Africa. The 17DYF vaccine, a live attenuated virus immunization, is
administered at licensed facilities to travelers to areas at risk for disease.
It is considered a relatively safe vaccine, but recently there have been
reports of severe illnesses in some vaccinees. These investigators, from the
CDC, Emory School of Medicine, and the US FDA, conducted a survey of reported
complications due to YF vaccine and showed that the risk of significant illness
is highest in older travelers.
The Vaccine
Adverse Event Reporting System (VAERS) was established to monitor significant
reactions to all vaccines in the United States, and is a passive reporting
system monitored by the authors' organizations. The authors used reports
submitted between 1990 and 1998 to establish the numerator of rates of
vaccine-related illness, then estimated the age distribution of vaccinees by
polling a sample of 13 travel clinics and determined the total number of doses
used from manufacturer records. Types of vaccine adverse events were defined
prospectively, and 3 physicians reviewed each clinical record blindly and
independently while assigning type of reaction to each reported case.
During the
study period, there were 166 reports of YF vaccine adverse events, but only 71
met study criteria, with 56 occurring in military personnel, 28 not related to
YF vaccine, and 11 in children or patients of unknown age. Systemic and
neurologic events accounted for 35 cases; other reactions, including
hypersensitivity, occurred in 36 cases. Compared with the reference age group
of 25-44 years of age, those aged 65-74 had a 12.3 relative risk (reporting
rate ratio) and those > 74 had a relative risk of 32 of having a serious
systemic adverse event. Other adverse events were not more common in older
patients receiving YF vaccine, nor were they more common in older adults administered
another common traveler's vaccine, hepatitis A. The estimated rate of serious
severe reactions from YF vaccine in the age group 25-44 was 0.29/100,000 doses,
while in the age group > 74 it was 9.06/100,000.
As travel
becomes increasingly popular for healthy, older people, travel clinics should
be circumspect in their use of live vaccines for the oldest travelers. Occult
immune senescence might place older persons at higher risk for serious,
possibly fatal reactions. Before giving live vaccine, the travel physician
should determine whether the live vaccine is really necessary for the
anticipated travel.
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INFORMATION, DATA, AND MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR
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KNOWLEDGE OR OPINIONS OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED
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