(December 2005) Polio eradication experts are breathing a sigh of relief: The disease’s latest resurgence, which began in 2003 and spread to a dozen previously polio-free countries, appears to have been quelled in all but Indonesia and Nigeria.

But questions remain about when polio can be eliminated globally, with routine vaccination rates in some developing countries not even reaching 50 percent of children ages 5 and under.1 It now appears that the global eradication of polio will not be declared until 2008 at the earliest, missing a 2005 deadline set earlier by the World Health Organization (WHO).

“It’s been frustrating,” says Steve Strickland, the UN Foundation’s senior liaison officer to the international organizations and national governments supporting the eradication effort. “Every year since 2002 we have thought this will be the last year of the campaign. The dynamic nature of the disease, problems with funding, and the competition for resources among poor countries have all worked against us.”

However, the decisive weapons used in beating back the recent spread of polio—strong national immunization drives and the development of a new vaccine—are also giving hope that eradication is within reach. The consensus among polio experts is that the disease can still be eliminated everywhere except in Nigeria sometime next year—but only if funding and political will are adequate.

“All countries have to maintain high population immunity because outbreaks aren’t that far away,” says Oliver Rosenbauer, spokesperson for WHO’s polio eradication campaign. “This virus spread halfway around the world in less than two years.”

Causes of Recent Resurgence

Polio was close to elimination just two years ago, after a 15-year, $3 billion worldwide vaccination and surveillance campaign called the Global Polio Eradication Initiative (GPEI) had reduced worldwide polio case numbers from an estimated 350,000 in 1998 to 784 in 2003. The disease, which had been endemic in more than 125 countries in 1988, remains so in only six countries— Nigeria, Niger, Afghanistan, India, Pakistan, and Egypt (see figure).


Countries Reporting New Polio Cases, 1988 and 2004

1988

2004

Source: Global Polio Eradication Initiative.


The recent outbreak began in northern Nigeria, where several Muslim-majority states stopped vaccinating for polio in 2003 and 2004 because of rumors that the vaccines were HIV-infected or part of a Western-inspired plot to sterilize Muslim girls. The rumors—sometimes promulgated by local politicians—brought vaccination rates in northern Nigeria to below 50 percent of children under age 5.2

At the same time, GPEI—which is sponsored by the United States, other donor countries, and private groups such as Rotary International and the Bill & Melinda Gates Foundation—was facing funding shortfalls, and steered resources away from countries bordering Nigeria to efforts in endemic countries. So when Nigerians traveled abroad, the virus spread: Within 11 months, polio outbreaks had been reported from Guinea to Sudan to Botswana.3 “The decision to fund endemic countries left a large pool of susceptible countries,” says Carol Pandak, manager of Rotary’s PolioPlus program.

And outbreaks continued to grow into this year as Muslims came together in large numbers for the hajj, the annual Muslim pilgrimage to Mecca. Yemen, which was declared polio-free in 1996, had reported 473 cases this year as of Nov. 15—more than one-third of the world 2005 total of 1,499 cases (see table).


2005 Worldwide Polio Cases, by Country*

Total Global Cases 1,499
Nigeria (endemic) 560
Yemen (importation) 473
Indonesia (importation) 288
India (endemic) 47
Somalia (importation) 42
Sudan (re-established transmission) 26
Pakistan (endemic) 19
Ethiopia (importation) 18
Angola (importation) 9
Niger (endemic) 6
Afghanistan (endemic) 4
Mali (importation) 3
Chad (re-established transmission) 1
Eritrea (importation) 1
Cameroon (re-established transmission) 1
Nepal (importation) 1

*As of Nov. 15, 2005
Source: Global Polio Eradication Initiative (2005).


In March, Indonesia reported its first case in more than a decade. By mid-November, the outbreak there had ballooned to 288 cases, spurring Vietnam and the Philippines to launch their own proactive immunization campaigns. For the first time, the number of cases reported in endemic countries was lower than the number reported in reinfected, previously polio-free countries. (A recent outbreak among four children in Minnesota appears unrelated to the worldwide outbreak.)

A Two-Pronged Response Stems the Tide

Rapid and large-scale immunization sweeps across all affected countries seem to have stopped most of the outbreaks, aided by a new polio vaccine targeting the poliovirus strain (Type 1) that fueled the resurgence.

Starting in mid-2004, vaccination rounds across 24 countries have reached as many as 95 million children in Africa—including in conflict zones such as Cote d’Ivoire and Sudan.4 Tens of millions more are being immunized in ongoing drives on the Arabian Peninsula and Indonesia. And the effort will continue: For instance, Saudi Arabia has announced that it will vaccinate those ages 15 and under who are making the hajj to Mecca in December and January.5

Great progress has also been made in polio-endemic countries such as India, Pakistan, and Egypt, where there has not been a new case reported since January 2005. The new vaccine—monovalent Oral Polio Vaccine Type 1, or mOPV1—has played a large part in these gains while also achieving dramatic results in importation countries such as Somalia, Indonesia, and Yemen. Yemen has not reported a polio case since August, and Somalia has been able to confine its outbreak to the city of Mogadishu.

“Countries have really stepped up,” says Pandak, “and the political will and commitment are there.”

Inadequate Vaccination Drives in Indonesia and Nigeria

But parts of Indonesia and northern Nigeria remain sticking points. Only 75 percent to 80 percent of Indonesia’s children get routine polio vaccinations, and the disease continues to spread on Sumatra Island despite a series of national immunization drives in which 750,000 volunteers have vaccinated 24 million children—97.4 percent of those targeted. Experts say that civil strife, a decentralized health system, additional rumors about the vaccine’s safety, and a slow response after the initial outbreak have presented obstacles on Sumatra.6

Northern Nigeria—where both Types 1 and 3 are endemic—also continues to record new polio cases despite the resumption of vaccination rounds over a year ago and the endorsement of those rounds by local politicians and Muslim leaders. (Of the three major types of poliovirus that afflicted the world in the 20th century, only Type 2 has been eradicated.) While Nigerian cases have dropped from 678 in 2004 to 550 over the same period this year, observers remain concerned that Nigeria lags the progress made in other endemic countries.

“Nigeria is the number one problem,” says Pandak. “The quality of their immunization activity is not high enough. A lot of the importation problems will be solved if you solve the Nigeria problem.”

According to analysts, northern Nigeria presents several complicating factors to current eradication efforts: a weak health infrastructure, a nomadic populace, the effectiveness of the smear campaign against vaccination, and lack of training for many delivering the immunizations. While the latest round of immunizations reached more than 90 percent of the children under age 5 in Nigeria’s Kano state—the northern state hardest-hit by the outbreak—the northern part of the country remains undervaccinated.7

“They’ve done a very good job addressing the political question, but the local religious and political leaders were very effective in getting out the message that the vaccine is unsafe,” says Pandak. “The public is suspicious about the reversal.”

Next Steps and Lessons Learned

In the immediate term, polio experts say, raising immunization rates in countries at immediate risk is essential to achieving a polio-free world. Rotary International and the Global Polio Eradication Initiative have recommended fresh immunization rounds in northern Nigeria as well as the Horn of Africa, where routine immunization rates are low.

Meanwhile, analysts are sifting through the lessons learned from the recent outbreak. Their key conclusions include:

  • The weak health infrastructures of many developing countries can compromise routine immunization programs. “Many countries do not have the capacity to maintain polio-free status,” says Pandak. “And some countries are just now working with their local community and religious leaders. It’s important to get those people to buy in early.”
  • Quick response to outbreaks is critical. “As soon as there’s an outbreak anywhere, you have to jump on it quickly—within two weeks,” says Strickland. “In Indonesia, it took them two months. WHO has been saying to all its [GPEI] partners that we can’t rely on national health systems in these cases.”
  • Efforts in polio surveillance, although improving, still have dangerous gaps. Pandak says that, while the quality of surveillance has essentially doubled in recent years, countries such as Somalia and Nigeria remain concerns. “Surveillance will be the key to global certification,” she says.

Funding Shortfalls, Yet Renewed Optimism

Whether GPEI will receive the $200 million needed in 2006 to accomplish these goals—including a $75 million funding gap for the first quarter—remains in question. Leaders of the G8 countries pledged in July to fund the GPEI until polio was eliminated, and Rosenbauer and others say they are relatively confident that those and other pledges will translate into cash.

“It’s taken a year to clean up the mess from the first exportations,” Strickland says. “But we’re so close to eliminating the second disease after smallpox, there’s extra incentive to get the job done.”


Robert Lalasz is senior editor at the Population Reference Bureau.


References

  1. Donald G. McNeil, Jr., “A New Round in Polio Fights Yet to be Won,” The New York Times, May 3, 2005.
  2. Global Polio Eradication Initiative (GPEI), Global Polio Eradication News 24 (Summer 2005): 3.
  3. McNeil, “A New Round in Polio Fights Yet to be Won.”
  4. GPEI, “Stakes Remain High to Wipe Out Polio in Africa ” (press release, Apr. 8, 2005), accessed online at www.polioeradication.org, on Oct. 28, 2005.
  5. Donald G. McNeil, Jr., “Muslims’ New Tack on Polio: A Vaccine en Route to Mecca,” The New York Times, Aug. 20, 2005.
  6. Celia W. Dugger, “Indonesia Mobilizing Against New Polio Outbreak,” The New York Times, Aug. 30, 2005; and Alan Sipress, “Indonesia Makes Progress Against Polio,” Washington Post, Sept. 6, 2005.
  7. Craig Timberg, “Nigeria Picks Up the Pace in the War Against Polio,” Washington Post, Aug. 24, 2005.