30 September 2011

The chance to eradicate polio once and for all must not be wasted, write Dr Robert Scott, of the Rotary International PolioPlus Committee and Dr Bruce Aylward, of the WHO

In 1980, the world was certified as being officially free from smallpox. Polio could, and should, be next.  Strategies that tackle the remaining risks to a polio-free world are already bearing fruit, but these need  to be fully financed and implemented.

Unlike most diseases, polio has several unique characteristics that make it a good candidate for  eradication. Poliovirus cannot survive for extended periods outside the human body, and its infection  period is relatively short. Furthermore, oral polio vaccine is not only incredibly safe and effective, but,  because it is orally administered, can be dispensed by anyone, including volunteers. Polio is a dreadful  disease that can maim and even kill. Eradicating polio would benefit children across the entire world –  no child need ever again know the pain of polio-paralysis.

Inspired by the eradication of smallpox and the progress of polio eradication in the Americas, Rotary  International began its PolioPlus campaign – an effort to immunize all the world's children against the  disease – in 1985. Three years later, at the annual meeting of the World Health Assembly, the  governments of the world together resolved to launch the Global Polio Eradication Initiative (GPEI).  Since that time, the spearheading organizations of the GPEI – the World Health Organization (WHO),  Rotary International, the US Centers for Disease Control and Prevention (CDC) and UNICEF – have  worked with national governments towards the goal of ending polio  for good.

Progress was dramatic – most countries interrupted indigenous virus transmission within two or three years of starting mass immunization campaigns with oral polio vaccine (OPV). One of the three serotypes (wild poliovirus type 2) was eradicated in 1999. The estimated number of children who were paralyzed by polio in 1988 was 350,000 – by the year 2000, the incidence of polio globally had decreased by 99%. By 2005, transmission of indigenous wild poliovirus had been interrupted in all but four 'endemic' countries: India, Nigeria, Pakistan and Afghanistan.

In the next few years, however, progress stalled in some of the worst-affected areas: Afghanistan and Pakistan struggled with conflict and insecurity; reduced vaccine efficacy was a thorny problem in northern India due to unique environmental and demographic conditions; the Nigeria program met with political resistance in some northern states; and all four endemic countries struggled with weak management and oversight of mass-vaccination campaigns at the local level. Furthermore, wild poliovirus exported from northern Nigeria and northern India caused multiple outbreaks in previously polio-free countries across Asia and Africa, undoing much of the progress achieved, with a concomitant huge increase in costs to the program.

In 2008, the World Health Assembly decided that a new strategy was needed to complete the eradication effort. Over the next year, a thorough, independent evaluation of the programme was conducted, including a look at the major lessons learned in the previous 20 years. This culminated in the release of a new strategy, the Global Polio Eradication Initiative Strategic Plan 2010-2012, and the appointment of a new board to independently monitor the plan's implementation.

A cornerstone of the new strategy is to tailor approaches to the political, social and geographic context of the few remaining pockets of the world with indigenous polio, while strengthening resilience in polio-free areas. Where weak management and oversight compromise the quality of vaccination campaigns, dedicated advocacy work to engage health and political leaders – especially at the sub-national (province and district) level – has been essential.

In southern Afghanistan and northwestern Pakistan, insecurity and active conflict was, and continues to be, the main barrier towards building sufficient population immunity. Programme managers in these areas have responded by continually introducing innovative tactics, such as vaccinating children at short intervals whenever an opportunity presents itself and negotiating for access through any neutral and credible mediators.

To protect those countries most at risk of re-infection – especially the 'importation belt' of sub-Saharan Africa – vaccination campaigns continue to take place in order to maintain population immunity. As was seen by the temporary re-infection of Russia in 2010, poliovirus can travel far, and no country is without risk until eradication is complete. Maintaining high levels of routine immunization and disease surveillance is, therefore, a priority everywhere.

The GPEI also relies heavily on three cross-cutting approaches to assist governments in stamping out polio. The first is the massive deployment of technical assistance by international agencies to countries in order to help introduce, apply and monitor polio eradication strategies.

An agenda of innovation and research also drives polio eradication. This includes the fast-tracked development, testing and licensing of modified or new eradication 'tools', particularly vaccines, diagnostic tests and related technologies. Programmatic innovations that have proved critically important include systematic house-to-house vaccine delivery and special strategies to reach underserved and migrant groups at highest risk of being missed by polio vaccination campaigns.

Finally, an aggressive advocacy agenda has engendered crucial support by political bodies such as the African Union, the Organization of Islamic Cooperation, the Commonwealth, and especially the G8.  Rotary International, with its 1.2 million members in more than 200 countries working tirelessly at the grassroots level, has frequently been the leader in this effort, which also mobilized key individuals, from UN leaders and international personalities to local political, community and religious leaders in support of eradication.

At the midpoint in the implementation of the strategic plan, the results are promising. India and Nigeria each saw decreases in polio case numbers of around 95% from 2009 to 2010. Political support from all polio-affected countries is fast gaining momentum. Bivalent oral polio vaccine, first used in December 2009, is proving to be extremely effective, especially in bringing wild poliovirus type 3 down to unprecedentedly low levels.

The counterpoint to this reality is the fact that still not enough children are being vaccinated in some areas. Ongoing, uncontrolled polio transmission in Chad and Pakistan is a major concern – although each has produced a new emergency action plan this year to stop polio. In Nigeria, gaps in disease surveillance and inadequate vaccination have helped case numbers creep upwards again in 2011, especially in the northwestern states. The government is addressing this outbreak with reviews of surveillance and greater attention to the details of vaccination campaigns in high-risk zones.  Given the new tools, tactics and commitment in infected areas, funding is now the major decider of whether this venture succeeds. The program is currently facing a US$590m funding gap for 2011-2012. This gap pales compared to the global savings of US$40-50bn in the 25 years immediately following eradication.

Meanwhile, the benefits of eradicating polio go beyond the economic and reach into other areas of public health. Polio-funded staff and infrastructure are used to distribute other health measures such as vitamin A – which alone has averted two million childhood deaths – and to assist in emergencies such as the 2009 floods in Pakistan and the 2011 drought in the Horn of Africa. Similarly, the strategies developed to reach every last child in remote areas, or to track mobile and migrant
populations, are being adapted to provide other health interventions. The polio program also plays a significant role in strengthening routine immunization. Polio eradication, while protecting future generations from the devastation of polio-paralysis, paves the way for making sure that every child, regardless of socioeconomic status, religion or gender, receives equal access to health.

Polio eradication is both a worthwhile goal and an achievable one. The remarkable reduction of polio cases worldwide from 1,000 per day to three per day indicates quite clearly that the disease can be eradicated forever. The GPEI has the will and the skill to finish the job, including a new, more efficacious vaccine and a strategic plan that is already producing striking results. Provided there is adequate funding and access to all children, the world could soon be free from the threat of polio.