Washington: The nearly two-decade-old global effort to eradicate polio, now in a difficult endgame stage in trying to eliminate the last places where the virus still paralyses children, received a major financial boost on Monday with a $200 million (nearly Rs792 crore) commitment from the Bill & Melinda Gates Foundation and Rotary International.

The donation, while hailed by global health officials as a major step, still leaves a substantial funding gap over the next two years. It also comes at a time when several scientists have raised new concerns about whether the strategy to wipe out polio was the correct one.

Leading the charge: William H. Gates Jr. co-chairman, Bill and Melinda Gates Foundation

Speaking to reporters, Dr Robert Scott, chairman of Rotary Foundation, said of the Gates foundation’s grant, “$100 million (in donation) takes our breath away... The job is 99% completed. But the polio cases representing the final 1% are the most costly."

Bill Gates Sr, co-chairman of the Gates foundation, said polio eradication was an “achievable goal," adding that he hoped the grant would challenge governments to make good on earlier commitments to fund the programme.

Challenges, opportunities

WHO officials have estimated eradication efforts will cost nearly $1.3 billion in the next two years, a staggering amount considering that the wild polio virus is transmitted in four countries—Nigeria, India, Pakistan, and Afghanistan—and that 735 cases have been reported this year.

The health organization said that even with the Gates grant and Rotary’s commitment, the programme is challenged by a $650 million shortfall in the next two years.

The US, Germany and Russia have fulfilled pledges to fight polio and Japan was close to meeting its promise. But WHO officials said the UK, Canada and France have lagged far beyond on their pledges.

The polio eradication programme has made impressive gains recently, reducing by more than half the number of cases globally this year, compared with 2006; cutting Nigeria’s cases to almost a quarter of last year’s numbers; and knocking out polio type I—the most virulent form of the disease—in highly populated areas of Uttar Pradesh.

The crowded urban environment in the state, coupled with high rates of childhood diarrhoea, make it such a difficult place to fight polio that “if the polio virus was to pick its last stand, its Alamo, so to speak, it would head for Uttar Pradesh," said Bruce Aylward, director of WHO’s polio eradication initiative.

Looking for alternatives

But the campaign’s switch to a vaccine that targets only polio type I has yielded strong results.

But the announcement earlier this year that roughly 75 children in Nigeria contracted polio from the oral vaccine sent a chill through many public health specialists and renewed doubts of some whether polio could ever be eradicated. Some called for the eventual switch to using the injectable polio vaccine, now used in the US and many countries in the West.

The injectable vaccine cannot transmit polio; cases of vaccine-acquired polio from the oral vaccine are extremely rare, but children who are infected this way can transmit it to others. The oral polio vaccine has one major advantage, especially in the developing world—it costs about ¢16 (about Rs6) a dose, compared with $2.75 for the injectable vaccine.

Still, said Ellie Ehrenfeld, a polio researcher at the National Institutes of Health (NIH), “while the oral vaccine was just the right thing to do to bring us almost to the end, it is incompatible with the eradication of polio wild virus. We need to change the endgame strategy—by switching back to" to the injectable polio vaccine. Aylward disagrees. He said the current tactics will end polio and that greater use of the injectable vaccine was still “a couple of years off." The issue was taken up on Tuesday and will be discussed on Wednesday in Geneva as the WHO convenes a group of polio specialists.

©2007/The Boston Globe