Vaccine safety is increasingly a major aspect of immunization programmes. Parents are becoming more aware of safety issues relating to vaccines their babies might receive. As a consequence, public health initiatives have had to take note of pressures brought to bear by individual parents and groups. Now we document a new phase in vaccine safety where it has been used to achieve political objectives. In 1988, the World Health Assembly declared its intention to eradicate poliomyelitis from the globe by the year 2000. This goal had to be postponed to 2005 for a number of reasons. Although the progress has been spectacular in achieving eradication in almost all nations and areas, the goal has been tantalizingly elusive. But arguably the most difficult country from which to eradicate the virus has been Nigeria. Over the past two years, tension has arisen in the north against immunizing against polio using the oral polio vaccine (OPV). Although this vaccine has been used in every other country in the world including other Muslim states, some religious leaders in the north found reason in August 2003 to advise their followers not to have their children vaccinated with OPV. Subsequent to this boycott, which the Kano governor had endorsed for a year and then ended in July 2004, cases of polio occurred in African nations previously free of the virus, and the DNA finger-print of the virus indicated it had come from Nigeria. In other words, Nigeria became a net exporter of polio virus to its African neighbours and beyond. Now the disease has spread to a dozen formerly polio-free countries, including Sudan and Indonesia. We show that, while the outward manifestations of the northern Nigerian intransigence were that of distrust of vaccine, the underlying problem was actually part of a longstanding dispute about political and religious power vis a vis Abuja. It is unlikely that polio transmission will be interrupted by 2005 if this dispute is allowed to run its course.