Minimum smallpox vaccination is best strategy for now, experts say

PHILADELPHIA ? (Jan. 21, 2003) The current smallpox vaccination policy of vaccinating a very limited number of first responders to a potential smallpox outbreak and avoiding mass vaccination is the best vaccination strategy, say two smallpox experts in an article in Annals of Internal Medicine.

The article is released today online at www.annals.org and will be published in the March 18, 2003, hard copy edition of the journal.

In the absence of a known threat of smallpox exposure, mass vaccination of the entire population or selective or voluntary vaccination would be dangerous to many who might get the vaccine, their contacts and the public health initiative, say J. Michael Lane, MD, MPH and Joel Goldstein, MD, in the article.

The authors cite studies from the 1960s documenting the complications associated with smallpox vaccination, including spread to close contacts, and note that the risks of vaccination may be greater today because of the larger number of people with immunosuppression and atopic dermatitis.

Dr. Lane was formerly director of the smallpox eradication program at the Centers for Disease Control and Prevention. Dr. Goldstein, a practicing pediatrician and a clinical instructor in pediatrics at Emory University School of Medicine, was involved with the evaluation and treatment of smallpox vaccination complications at the CDC.

Previous studies have shown that smallpox does not spread rapidly under natural conditions; in fact, it takes a “leisurely” course, the authors say.

Thus, a “reasonable mix of judicious vaccination of close contacts and effective isolation of patients can readily stop outbreaks within two infective generations,”(about four weeks), the authors say.

Because of the morbidity and mortality associated with vaccination, in the absence of a documented threat of bioterrorism, the authors conclude that appropriate immunization of a small number of medical workers is an adequate and reasonable policy. “Any increase in vaccine usage will lead to an increase in side effects and possibly death,” said Dr. Goldstein. “We must be very careful about the vaccination strategy we select.”

At the same time, the authors recommend a systemic public health effort to build vaccine supplies, institutionalize vaccine production capacity, develop and expand laboratory expertise and train public health authorities and first-response clinicians.

Besides evaluating the risks and benefits of several pre-attack vaccination strategies, the authors discuss how smallpox is transmitted, kinds of vaccines, normal vaccination response, and the three types of rare but potentially fatal complications that can follow vaccination.