Promise of eradicating polio receives setback

The World Health Organisation (WHO) 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. Centres 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 immunisation 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 bio-terrorism.

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.

For text (WSJ subscribers) http://online.wsj.com/article/0,,SB1018907094309907720-polio,00.htm

For more on Public Health http://www.ncpa.org/iss/hea

FMF Policy Bulletin\23 April 2002