Promise Of Eradicating Polio Experiences Setback
April 16, 2002
The World Health Organization had high hopes of eradicating polio this year. If it could do so -- and no new cases emerged over the next three years -- it could certify the world polio-free in 2005.
But that timetable may be in trouble. The U.S. Centers for Disease Control and Prevention is reporting a new outbreak on the Caribbean island of Hispaniola -- which is divided between the Dominican Republic and Haiti. The source of the outbreak is a real surprise: the virus may have re-emerged from one of the two polio vaccines in use.
A live form of the virus is used to produce the vaccine -- and it is supposed to be too weak to cause the disease. But on Hispaniola, the virus may have "back-mutated," undergone a series of genetic changes and re-emerged in a virulent form. Such a process may also have played a role in polio outbreaks in recent years in the Philippines and Egypt.
This development suggests to some experts that vaccinations should be stopped altogether.
- The WHO estimates that there were 1,000 cases globally last year -- although it expects to reduce that figure to 600.
- By comparison, there were 350,000 cases reported in 1988 -- and half a million per year in the early 1980s.
- If polio were truly eradicated, the savings in immunization costs would be $1.5 billion annually.
- But even if naturally-occurring polio were eradicated, scientists fear that the disease could return through an accident or bioterrorism.
Even today, between 5 percent and 10 percent of children in developed countries aren't immunized -- while in many poor countries half the children aren't protected.
So there is a debate in scientific circles between those who contend that it would be pointless to continue vaccinations once the disease is eradicated and others who say vaccinations should continue.
Source: Gautam Naik, "Polio Cases Roil Debate on Ending Vaccine Program," Wall Street Journal, April 16, 2002.
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