Mission Impossible?
An international campaign to rid the world of polio has made dazzling progress. But some experts question whether the scourge can ever be eradicated
- By Smithsonian magazine
- Smithsonian magazine, February 2003, Subscribe
(Page 2 of 2)
But, ironically, the oral vaccine, which contains three strains of weakened polio virus, poses a challenge to the eradication effort: the weakened virus can mutate in the human gut into a more virulent form and spread to others, causing poliomyelitis. (For that reason, children in the United States receive only the injectable, Salk vaccine.) Dr. Donald “D.A.” Henderson, the Johns Hopkins University infectious disease specialist who led the successful effort to eradicate smallpox, says the potential for polio outbreaks tied to the oral vaccine is one of several reasons that eliminating the disease entirely might be impossible; he also cautions that people with immune disorders can harbor the virus for years, possibly transmitting it after the inoculation campaign ends. Henderson, who applauds the “great progress made in the efforts to stop transmission,” nonetheless argues for curtailing the eradication campaign and focusing instead on “controlling” the disease. In addition, Henderson, who advises the White House on bioterrorism, suggests that some funds earmarked for eliminating polio entirely might be better spent against AIDS, tuberculosis and malaria, which are far more common than polio in the developing world.
Advocates of polio eradication counter that outbreaks caused by the oral vaccine are extremely rare, with only three documented worldwide since 2000, resulting in fewer than 30 cases of paralysis; to advocates, the question is not whether to continue the campaign but, rather, how to phase out the oral vaccine after poliomyelitis cases disappear. Besides, they say, the success of eradicating polio from the Western Hemisphere (in 1994), from the PacificBasin including China (2000) and from Europe (2002) shows that the same can be done for the rest of the world. Henderson’s “ridiculous” suggestion, says University of Pennsylvania polio expert Dr. Neal Nathanson, is “distracting and demoralizing to all the people working to make that goal a reality.” To give up now, says Dr. Stephen Cochi, director of global immunization at the Centers for Disease Control and Prevention, would be like “snatching defeat from the jaws of victory.”
Salgado, for his part, says it’s cynical to ease up “so close to the edge of finishing.” He admits he’s no expert, but he allies himself with the physicians, vaccinators and others who, as he puts it in his Portuguese-accented English, “are the guys of the good side of the planet.”
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