Infectious Diseases: Two Faces of Smallpox

• Share

(2 of 2)

Dry the Wellsprings. The U.S. has a different problem from Britain's, but it is no less difficult. There have been no smallpox deaths in the U.S. since 1949, and public health authorities attribute the immunity to universal vaccination. A more likely explanation is that 95% of U.S. civilians couldn't catch smallpox if they tried. The virus travels only from man to man—through the air, by physical contact, from the dust of drying pox scabs, and thus from clothing and bedding—and the average American never gets within 1,000 miles of a case. What counts most is that no one is allowed to enter the U.S., whether returning resident, immigrant or transient, without proof of recent vaccination.

For travelers, this makes good sense, says the University of Colorado's Dr. C. Henry Kempe. Not for the stay-at-home. Vaccination itself is not always harmless. It may cause a fatal reaction in young children with eczema, and at later ages a severe or deadly encephalitis. In 1962, Britain had 15 vaccination deaths. Since the last American smallpox death, Kempe estimates, there has been an average of 15 deaths each year from vaccinations. Taking the traditional smallpox death rate of 30%, this means, he argues, that there would have had to be 600 or more cases of smallpox in little more than 15 years.

Smallpox, like polio, can indeed be eradicated. But while such countries as India (with massive support from Russia, which has supplied more than 400 million doses of heat-resistant, freeze-dried vaccine), and others in Asia and Africa, try to dry up the wellsprings of the epidemics, highly sanitized Western countries can abandon dangerous routine vaccinations only if they enforce rigid safeguards on travelers.