Is Polio Eradication Realistic?

Published in Science, this 2-page paper critically examines the rationale behind - and the (in)effectiveness of - the global polio eradication campaign, which was launched by the World Health Organization (WHO) in 1988 with the goal of wiping out polio by 2000. The authors here question the wisdom of this approach, arguing that polio might never be eradicated, and that attention should instead be turned to effective control. In this context, a number of communication-related challenges and components seem to emerge.

The authors begin by citing statistics to demonstrate the failure of the campaign, despite its high cost. For instance, in 2005 a total of 1948 cases of poliomyelitis were reported in 16 countries; from January 1 through March 21 2006, 91 total cases were reported, as compared with 52 from January to March in 2005. These efforts have, to date, cost US$4 billion in international assistance; the cost doubled between 2000 and 2005. They then outline 4 main reasons why the eradication of polio has proved so much more difficult than the eradication of smallpox:

1. The high proportion of subclinical cases - Due to the existence of 100 to 200 "invisible" poliovirus infections for every case of paralysis, "surveillance and containment are impossible". In India, although repeated rounds of National Immunization Days (NIDs) were carried out between 1995 and 2005, cases have continued to be found.
2. Vaccine-derived polio - There are difficulties associated with using the trivalent Sabin oral vaccine (OPV); events such as outbreaks resulting from vaccine strain mutations "require careful study, as their cause and likelihood of occurrence are unclear. In consequence, policies to be followed after termination of polio transmission are uncertain."
3. Population/political changes - The polio eradication programme started as different
   countries were assuming a greater degree of political independence - a circumstance that has led to such complexities as the suspension of polio vaccination in northern Nigeria (2003-04) because of a mistaken belief that the vaccine was unsafe. This misunderstanding surely raised communication issues that could have been anticipated and addressed along the way.
4. Prolonged duration of the global programme - In the words of the lead author, "The duration of an eradication program should not be too long, perhaps in the range of 10-15 years...it is difficult to sustain a high level of enthusiasm throughout the period."

In light of these difficulties and shortcomings, the authors suggest that the global eradication programme for polio be discontinued. To make this case, they begin by highlighting some of the strategic challenges associated with overseas aid assistance for vaccination programmes. Specifically, "The monetary figures for international assistance hide the reality that recipient nations, particularly poor nations in the sub-Saharan area and Indian subcontinent have to digest such assistance with extraordinary mobilization of their own health resources." This fact, according to the authors, explains the "great disparities" in routine immunisation rates around the world, such as the fact that 90% of children in Europe have been protected against diphtheria, pertussis, and tetanus (DPT) and measles, as compared with about 50% in sub-Saharan Africa. The authors point out that the local mobilisation of resources required to receive/process this assistance also impedes development of other public health efforts, such as development of AIDS and malaria vaccines.

On the authors' "effective control" alternative to eradication, the first priority would be to continue the current emergency measures and limit the spread of polio in Africa, the Middle East, the Indian subcontinent, and Indonesia. Once the goal of fewer than 500 cases in fewer than 10 countries is achieved, the authors suggest that all polio eradication elements become part of the new Global Immunization, Vision, and Strategy (GIVS) programme approved by WHO in 2005 (for a summary of this strategy, click here). As part of this approach, an international vaccine stockpile would be set up with OPV in case new outbreaks occur. OPV would continue to be used for routine vaccination in less wealthy countries until 2015, when progress toward the Millennium Development Goals (MDGs) will be evaluated.