Boosted by a new vaccine and an aggressive new strategy, the battle against polio is on the verge of victory in key regions across the world, sparking new hope of defeating one of the great scourges of the past century.
Polio outbreaks in Nigeria and India - two of the four countries where polio is still endemic - have been reduced to drastically smaller levels this year, with a 98 per cent decline in Nigeria and a 90 per cent decline in India.
The story of those successes could be a model for the final eradication of the crippling disease - a dream of humanity for decades. The new goal is to eliminate polio from the entire planet within the next two years. It's a goal that has often been postponed, but now appears within reach.
The global campaign against polio began in 1988 when more than 350,000 new cases were occurring every year. The effort achieved great progress in its early years, reducing the number of new cases by 99 per cent and eliminating the disease from most of the 125 countries where it still existed. But the campaign has stalled in the past decade. Polio cases were recorded in 23 countries last year - a discouraging setback.
Nigeria, the most populous country on the continent, is the only African country that never managed to eliminate polio even briefly. It is also a prime example of how superstition and religious extremism have jeopardized the fight against polio.
Islamic leaders in northern Nigeria organized a boycott of polio vaccinations in 2003, claiming that the vaccines were a Western plot to infect Muslims and make them infertile. Polio cases soon skyrocketed and spilled over to other African countries.
The number of new polio cases in Nigeria jumped from 355 to 792 within a year of the boycott. Hundreds of children were crippled as a direct result.
As recently as 2008, there were still nearly 1,000 new cases of polio in Nigeria. But the progress in the past two years has been remarkable. This year, only nine new cases have been recorded, and campaigners are confident of eliminating the disease from the entire country by next year.
"We feel very proud of what we've done," said Boubacar Dieng, immunization manager at the Nigeria office of Unicef, the United Nations children's agency. "It's still highly fragile, but I'm sure Nigeria will reach eradication. All indicators are very positive. I'm 100 per cent confident."
Nigeria was one of the first countries to receive a new vaccine that has been powerfully effective in combatting polio. It's a double-strain vaccine, allowing children to be simultaneously immunized against two of the three main polio strains with a single oral vaccine.
The vaccine has produced dramatic results in Nigeria and India during the past year. Only 39 new cases have been recorded in India this year, down from nearly 400 in the same period last year - similar to the decline in Nigeria. "It's a very effective, very valuable vaccine," Dr. Dieng said.
But the new vaccine is not the only reason for Nigeria's success. The polio campaigners have been aggressive in educating communities about the need for immunization. They persuaded Muslim leaders to drop their boycott and support the campaign. Some traditional Muslim leaders held public meetings in which they swallowed the vaccine themselves - or vaccinated their own children in front of the whole community - to prove that it is harmless.
Many Nigerian Muslim leaders were shocked during the annual Hajj pilgrimage to Saudi Arabia when they were pulled aside and given the polio vaccine by Saudi Arabian officials. "When they witnessed this," Dr. Dieng said, 'they realized how serious it is."
The education campaign in Nigeria was also boosted by polio victims themselves. Some victims went into villages, showing their withered legs, propelling themselves slowly on wheelchairs or rough blocks of wood. "Do you want your child to look like me?" they asked the villagers.
While the progress in Nigeria and India has been impressive, the fight against polio is still facing major challenges in Africa. Even as the disease is nearly beaten in Nigeria, it has emerged in new countries - including Angola and the Democratic Republic of Congo, which accounted for 48 of the 58 new cases in Africa over the past six months. A handful of new cases have also been reported recently in Uganda, Liberia and Mali.
New immunization drives were launched across Africa in late October and early November. More than 72 million children will be given the polio vaccine in 15 countries across the continent.
Nine of 10 countries hardest hit by polio are in Africa
CountryDALYs per 100,000 population*
1. Turkmenistan 22.2
2. Central African Republic 12.5
3. Nigeria 10.7
4. Sudan 5.9
5. Niger 5.6
6. Chad 4.8
7. Mali 3.8
8. Benin 2.5
9. Sierra Leone 2.3
10. Liberia 2.3
*Disability Adjusted Life Years: The sum of years of potential life lost due to premature mortality and the years of productive life lost due to disability.
Source: World Health Organization
Geoffrey York