Allergists Report Risks Associated with Smallpox Vaccine

Newswise — The live-virus smallpox vaccine may pose a risk for individuals taking high-dose corticosteroids, and those with certain skin disorders or who are immunosuppressed, according to a report published in this month's Annals of Allergy, Asthma & Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology (ACAAI).

The report by The Joint Task Force on Smallpox Vaccination for Allergists was issued by the ACAAI and the American Academy of Allergy, Asthma and Immunology (AAAAI) in response to the federal government's pre-event smallpox vaccination program and post-exposure concerns.

"The current smallpox vaccine has been licensed by the Food and Drug Administration (FDA) and had, in the past, been given safely to millions of individuals," said Daniel Ein, M.D., Washington, D.C., lead author of the report. "In the event of a terrorism attack or exposure, the risk of having serious vaccination complications must be weighed against the risk of experiencing a potentially fatal smallpox infection."

Of particular concern are individuals with active eczema or atopic dermatitis, or a history of these conditions, or other exfoliative skin conditions, are immunosuppressed, or have a serious allergy to any component of the vaccine.

"Patients with atopic dermatitis are at a greater risk of contracting vaccinia infection, and also of spreading the virus, than are persons with healthy skin. Mortality rates among those with atopic dermatitis are likely to be the highest in children younger than 5 years," Dr. Ein said.

"Since one of the primary immunologic protective mechanisms to the virus is cell-mediated (T-cell) immunity, patients with this comprised immune response may be more susceptible to smallpox vaccine complications," he said.

Smallpox is a contagious disease caused by the variola virus, which has a 30 percent mortality rate. Preventable with vaccination, naturally occurring smallpox was eradicated from the planet by 1980.

High-risk exposure consists of direct and prolonged face-to-face contact. According to the report, the virus can be transmitted to intimate contacts of the vaccines, and is particularly dangerous if such contacts are themselves immunocompromised. The Task Force recommends potential vaccine recipients should not be immunized if their spouses, children or other household contacts have diminished immunity.

Although contact transmission by a vaccinated health care provider has been documented in the past, there has been no documented transmission of vaccinia virus from a health care provider to a patient or coworker in recent military or civilian programs. Authors attribute this to more stringent guidelines including education of vaccines about site care and hand-washing practices.

Since infected individuals with an early-onset rash might see an allergist-immunologist for diagnostic evaluation, they, like other health care workers, are considered at high risk of exposure if smallpox is reintroduced into the population.

Patient information on allergic diseases including asthma is available by calling the ACAAI toll free number at (800) 842-7777 or visiting its Web site at http://www.acaai.org.

The ACAAI is a professional medical organization comprising nearly 5,000 qualified allergists-immunologists and related health care professionals. The College is dedicated to the clinical practice of allergy, asthma and immunology through education and research to promote the highest quality of patient care.