Officials Say Drug Caused Nigeria Polio

A health official administers the polio vaccine to a child in a poor neighborhoodofn Lagos, Nigeria in this March 22, 2004 file photo. For doctors struggling to eradicate polio, fighting the paralytic disease usually means vaccinating children in war-torn regions, convincing governments to pay attention, and begging donors for money. But a recent polio outbreak in Nigeria revealed another potential problem: the vaccine commonly used against it. (AP Photo/Saurabh Das, File) (Saurabh Das - AP)

In Nigeria, the outbreak comes "in the wake of all the other problems they've had in," said Dr. Donald A. Henderson, who led WHO's smallpox eradication campaign in the 1970s.

In 2003, politicians in northern Nigeria canceled vaccination campaigns for nearly a year, claiming the vaccine was a Western plot to sterilize Muslims. That led to an explosion of polio, and the virus jumped to about two dozen countries.

Now, health officials' decision to keep quiet about the cause of the outbreak for so long may look suspicious.

Dr. David Heymann, WHO's top polio official, said that because the organization considered the outbreak to be a problem for scientists and not something that would change global vaccination practices, they thought it was was unnecessary to immediately share publicly.

CDC's Kew added: "The people who are against immunization may seize on anything that could strengthen their position, even if it's scientifically untenable."

Rumors are still rife among Nigerians that the vaccine is unsafe, and several religious leaders continue to lecture on its dangers. Another mass vaccine boycott could lead to further polio spread, derailing long-standing eradication efforts for good.

Nigerian health officials contacted by The Associated Press declined to comment on the situation.

"Convincing the Nigerians to take even more of this vaccine will be a tough sell," said Dr. Samuel Katz, an infectious diseases specialist at Duke University and co-inventor of the measles vaccine.

More than 10 billion polio doses have been given to children worldwide, and the vaccine has been credited with cutting polio incidence by more than 99 percent since 1988. Far more children are paralyzed by the wild polio virus than the virus spread by the oral vaccine. But no vaccine is risk-free.

WHO said that changing the vaccination strategy is unnecessary. "It would be nice if we had a more stable oral polio vaccine, but that's not the way it is today," Heymann said. "We will continue working the way we have been working because we don't want children to be paralyzed anywhere."