For years, the world has been on the brink of wiping out polio, the deadly disease that can paralyze and kill children.
At the World Health Organization's annual meeting of health ministers this week, experts are unveiling what they describe as a new strategy to get rid of the feared disease.
But others say there is little new and that if this effort fails, there are serious questions about whether to continue the campaign should be raised.
Some experts say eradicating polio is impossible and should be abandoned. With a new target of stopping the virus by the end of 2012, this may be WHO and partners' best chance to get rid of polio before donors run out of money and patience.
Since WHO, the U.S. Centers for Disease Control and Prevention, UNICEF and Rotary International set out to eradicate polio in 1988, they have come tantalizingly close. By 2003, cases had dropped by more than 99 percent. But progress has stalled since and several deadlines have been missed.
Polio has virtually disappeared from the West but is entrenched in a handful of countries, namely Afghanistan, India, Nigeria and Pakistan. The disease mostly hits children under five and is spread via dirty water.
WHO's new strategy targets problems in each country, provides more WHO monitoring, like more teleconferences, and holds governments more accountable. New outbreak response plans are also in place. Still, it is uncertain if more WHO oversight — which countries are free to ignore — will make a difference.
Others said WHO has always tailored programs to focus on local problems in different countries.
"I'm not sure how the new strategy differs from the ones adopted in 2007, 2004, and 1999," said Dr. Donald Henderson, who headed WHO's smallpox eradication program. He said the strategy's main elements have mostly all been seen before.
Polio cases fell sharply last year and experts are optimistic they may have turned a corner, though the disease's high season hasn't yet hit.
Dr. Paul Adovohepke, who heads UNICEF's polio team in Nigeria, said rumours about the vaccine's safety — which resulted in a year-long suspension of polio campaigns in 2003 — seem to have subsided. He has seen Nigerians ask vaccinators to go into their homes to give the polio vaccine to their kids. "(That) was not possible in 2003," he said.
But recent surprises, like an outbreak in Tajikistan, which had been free of the disease for years, show how unpredictable the effort remains. WHO says it is still possible to get rid of polio and that to give up now would set loose a deadly virus.
"You don't eradicate polio from 124 countries by doing it wrong," said Dr. Bruce Aylward, who directs WHO's polio department. "Either we finish eradication or we let the virus out and between 200,000 to 400,000 kids every year will be paralyzed."
Experts worry that as the effort enters its 22nd year, donors' patience and wallets are running thin. Sustaining the effort costs about $750 million every year.
The Bill & Melinda Gates Foundation, one of polio's top donors, could not say how long they plan to bankroll the effort, but said the next three years are "critically important." The foundation said their polio donations are reconsidered every year.
"You can't forever say you can do it and expect resources to keep coming in," said Scott Barrett, an economist at Columbia University who tracks polio. "Eradication efforts by definition cannot go on indefinitely."
The world is also very different now than when the drive to stamp out polio began. Two of the countries where the virus is spreading — Pakistan and Afghanistan — are plagued by conflict which make it nearly impossible to vaccinate enough kids.
Experts had also assumed the polio virus in the vaccine could never spark big outbreaks. They were wrong. Since 2005, a vaccine-derived epidemic has been spreading in Nigeria and similar epidemics are certain to erupt in the future.
"There might be a different assessment today about the feasibility of eradication, but I don't know what that decision might be," said David Heymann, who previously ran WHO's polio program.
Others said that to give up on polio would set a devastating precedent. Smallpox is the only disease ever to have been eradicated, and that took only a decade. Officials are still trying to get rid of guinea worm, and similar plans have been floated for malaria and measles.
Henderson suspects polio targets will be continually pushed back every few years. He said while officials are inching closer to eradication, future surprises could unravel the campaign. "What do you do when you have a tiger by the tail?" he asked.
Ellie Ehrenfeld, who sits on WHO's Advisory Committee for Polio Eradication, said the current situation is encouraging, but has a tinge of deja vu. "We have been very close before, and then things blew up," she said.
If polio is not stopped in the next few years, she said serious questions should be raised about whether the program should be scrapped. "It's theoretically possible to eradicate polio," she said. "Whether or not we can do it is entirely another matter."