Researchers Debate End To Polio Shots

August 8, 1997

NEW YORK (UPI) - Columbia University scientists say plans to stop polio vaccinations once the disease has been eradicated are short- sighted and could be dangerous.

In articles appearing in the journal Science, researchers say even after eradication, polio can still pose a natural threat or could be used as a biological weapon if vaccination programs cease.

The World Health Organization expects to eradicate polio worldwide by 2003. Already, the Americas are polio-free - only about 10 cases a year of polio occur and those cases are caused by the vaccine itself.

But Vincent Racaniello, professor of microbiology at Columbia, says there are reasons why eradication should not mean the end of vaccination:

-Use of oral vaccine - a key component of the WHO program to vaccinate huge populations - means that recipients continue to shed virulent virus into sewage systems and aquifers. Some people shed virus for weeks, months or years.

-Even after eradication, polio virus will still be found in thousands of laboratories around the world, creating the opportunity for an accidental outbreak into an unvaccinated population years after eradication.

-The genetic sequence of the polio virus is relatively short and the virus could be reconstituted by even a "casual terrorist" who could unleash a devastating biological weapon on an underprotected population.

Racaniello tells United Press International that even switching to an inactivated virus, which would control the shedding of virus, would not address the other issues.

He said WHO opposes the inactivated virus because it is more expensive and is prone to non-compliance because inoculations are more trying than swallowing a sugar cube impregnated with oral vaccine.