Sept. 13, 2002 — The risk of smallpox vaccination could outweigh the
benefits for patients with AIDS, atopic dermatitis, or
immunosuppression, according to a review in the September issue of the
Journal of Allergy and Clinical Immunology. Eczema
vaccinatum is a potentially lethal complication of smallpox vaccine
which can affect those with atopic dermatitis or similar conditions.
"The current CDC guidelines in the setting of a smallpox outbreak
include a recommendation to immunize anyone with contact regardless of
risk factor for an adverse event," lead author Renata J.M. Engler, MD,
FAAAAI, from the Walter Reed Army Medical Center in Washington, DC,
says in a news release. "Many expert groups are reviewing these
questions and considering the fine points of risk-benefit and what
other options exist to protect those patients who are at very high
risk for serious or even life-threatening smallpox vaccine
complications."
Groups especially vulnerable to adverse effects from vaccinia
include patients with congenital or acquired immune deficiency
diseases such as AIDS, those receiving immunosuppressive therapy for
organ transplantation or other conditions, those with active or
quiescent atopic dermatitis, and potentially those with similar skin
conditions affecting the epidermis.
In individuals with current or prior history of atopic dermatitis,
eczema vaccinatum can complicate smallpox vaccination or can develop
indirectly through exposure to someone who has recently been
vaccinated. After spreading unchecked throughout the skin, the
vaccinia virus can cause scarring, blindness, and even death. Vaccinia
immune globulin can mitigate or reverse these complications if given
sufficiently early.
Current CDC guidelines recommend withholding routine smallpox
vaccine from individuals with a current or past history of atopic
dermatitis. Nearly half of the population in developed countries,
where rates of atopic dermatitis have increased two- to three-fold
since the days of routine smallpox vaccination, could therefore be
ineligible, as could up to 15% of the U.S. population. Routine mass
smallpox vaccination could therefore be problematic, although
vaccination in some patients with atopic dermatitis may be justified
if the risk of smallpox infection is high, such as after a
bioterrorism attack.
The authors call for additional research on the immune response to
vaccinia to clarify why atopic dermatitis predisposes to eczema
vaccinatum and to develop preventive strategies.
"The very real dangers associated with the live vaccinia virus
vaccine may take on a greater urgency today than decades ago given the
current numbers of people with pre-existing medical conditions that
put them at risk for serious side effects," says co-author Julie
Kenner, MD, PhD, from the University of Hawaii in Honolulu. "It is
incumbent upon the medical community to protect our population to the
best of our ability against these potentially lethal vaccine side
effects, while at the same time, protect them from a very deadly
disease."
J Allergy Clin Immunol. 2002;110:357-365
Reviewed by Gary D. Vogin, MD
