Polio eradication: from deep trouble to likely triumph

In 2007, the initiative to eradicate polio was in deep trouble. As stakeholders gathered in Geneva for an urgent meeting, they faced a situation characterized by the highest number of polio cases reported in more than six years. Though the virus was endemic in only four countries, Afghanistan, India, Nigeria, and Pakistan, travellers from Nigeria and India had seeded outbreaks in an additional nine countries.

Polio eradication campaign, Afghanistan

WHO Afghanistan/R.Akbar

A strategy was in place, with clear guidance for the rapid detection of circulating poliovirus, the conduct of large-scale rounds of immunization using a type-specific monovalent oral vaccine, and the maintenance of highly sensitive surveillance. Still, progress was too slow.

The eradication effort in Nigeria faced a host of complex operational challenges, including vaccine refusals, especially in some northern states. But India was considered the most formidable challenge, given the country’s vast size, dense and mobile population, high birth cohort, and poor living conditions, all favouring high and efficient virus transmission. At the end of 2006, the country reported a 10-fold increase in new cases compared with the previous year. New evidence made some question whether eradication in India could ever succeed in the absence of dramatic improvements in sanitation and hygiene.

The spearheading partners and donors were tired. Staff, including tens of thousands of community volunteers, were demoralized. The initiative faced a funding shortfall of $575 million for 2007–2008. As the WHO Director-General told the meeting, “We have few opportunities to change the world for the better in a permanent way. If we don’t meet this virus with an immediate surge of commitment, the virus may win.”

Stakeholders rallied behind that call. WHO, Rotary International, the US Centers for Disease Control and Prevention, UNICEF, and the Bill and Melinda Gates Foundation renewed their commitment. The money was found. The Director-General visited the heads of state in endemic countries to secure high-level political commitment. The initiative struggled on.

2009 – 2010

By 2009, however, the world’s largest-ever global health initiative had clearly stalled. The strategies that had so effectively reduced polio incidence by more than 99% worldwide were not powerful enough to eradicate the disease in its last stubborn strongholds. New approaches would have to be found.

That same year, work began to develop a bivalent oral polio vaccine that could simultaneously target the two remaining serotypes in a single dose. The decision to do so was made at the start of the year. Evaluation, clinical trials, licensing, and production took place in record time. The new vaccine was introduced in Afghanistan in December, then rolled out programme-wide in early 2010.

Another important innovation came in 2010, when WHO established the Independent Monitoring Board of the Global Polio Eradication Initiative. The Board’s hard-hitting, straight-talking reports, issued twice yearly, took management to task at every level of the initiative, from donors, to international partners, to country operations. Finger-pointing was the norm. If a national eradication programme was “riddled with dysfunction”, the Board said so. It also demanded solutions, and harped when change came too slow. As the eradication machinery got better, the Board urged it to get great.

Emergency operations centres were established. Vaccination overage increased as did the accuracy of monitoring and reporting. National programmes shifted from counting the number of children covered to counting those that were missed.

The introduction of health camps – outreach services that provide basic health care, including simple diagnostics and medicines – helped allay suspicions that a singular and intense focus on polio must serve some sinister purpose. The co-delivery of free check-ups and medicines expanded the initiative’s contribution to include the treatment of common community ailments, like worm infections, scabies, anaemia, vitamin deficiencies, gastric pain, fevers, and diarrhoeal disease and malaria. Pakistan alone set up nearly 2,000 health camps dotting underserved areas in remote and destitute districts. The initiative’s call to “reach every child” now meant reaching entire communities with basic health care.

2012 – 2014

In 2012, polio eradication was put on an emergency footing. The Independent Monitoring Board had requested consideration of a resolution to “declare the persistence of polio a global health emergency”. The World Health Assembly acted on that request and adopted a resolution that declared the completion of poliovirus eradication “a programmatic emergency for global public health”. The resolution also urged countries with ongoing transmission to declare such transmission “a national public health emergency”. On its part, WHO was asked to rapidly develop a comprehensive polio eradication and endgame strategy. This was done in a plan covering the period 2013–2018.

The breakthroughs began. On 11 February 2014, India proved that there is no such thing as impossible. That date marked three years since the country’s last case of wild poliovirus. WHO declared that the territory of one of the world’s most densely populated countries was now free of a virus that had killed and crippled children for centuries. Many thought that day would never come: the virus was too firmly entrenched in India and the barriers to eradication were too great. The country’s dedicated leadership and determined vaccination teams proved them wrong.

“Being on the brink of triumph is not enough. The job will be done only when the entire world has been certified polio-free.”

Dr Chan, WHO Director-General

In July 2014, Nigeria – a country that had, over the years, re-infected 26 polio-free countries – reached what looked like its last case. The euphoria of finding no new cases continued for two years, but then dissipated in the second half of 2016, when four new cases were confirmed in Borno State, an area rendered virtually inaccessible by insurgency and a devastating humanitarian crisis. Genetic analysis indicated that the poliovirus had been circulating undetected for several years. Though the setback caused dismay, it redoubled the country’s determination to rid itself of poliovirus once and for all.

To secure the impressive gains, WHO convened in 2014 the first of several Emergency Committees, set up under the International Health Regulations, to look at ways to prevent the international spread of wild poliovirus. The Committee declared that doing so was a Public Health Emergency of International Concern, and recommended vaccination, prior to international travel, of all residents and long-term visitors in countries that were exporting wild poliovirus.

2015 – 2017

The global eradication of wild poliovirus type 2 was declared in September 2015. The Polio eradication and endgame strategic plan 2013–2018 called on countries to introduce at least one dose of inactivated polio vaccine into routine immunization schedules, strengthen routine immunization, and withdraw oral polio vaccine in a phased manner. In line with this plan, another major step forward occurred during the spring of 2016. During a short two-week period in April, 155 countries successfully switched from trivalent to bivalent oral polio vaccine, marking the largest coordinated vaccine withdrawal in history.

The primary purpose of introducing inactivated polio vaccine was to ensure that new birth cohorts had some protection against the type 2 poliovirus, either wild or vaccine-derived, hence mitigating the potential consequences of any re-emergence of type 2 poliovirus following the switch. Introducing at least one dose of inactivated polio vaccine would also boost immunity against poliovirus types 1 and 3, likely hastening their eradication.

In 2017, the eradication programme found itself in the extraordinary position of being closer to its goal than at any time in history. By early April, Afghanistan had reported three cases of wild poliovirus and Pakistan had reported two. Nigeria had not yet detected a case. To safeguard achievements, more than 190,000 polio vaccinators in 13 countries across West and Central Africa began a week-long campaign in late March 2017 to immunize more than 116 million children. The synchronized coast-to-coast vaccination campaign, one of the largest of its kind ever implemented in Africa, is part of urgent measures to permanently stop polio on the continent.

But being on the brink of triumph is not enough. The job will be done only when the entire world has been certified polio-free. The magnitude of that victory will no doubt boost world confidence in the power of public health – and vaccines – to build a better world.

Ebola outbreak in Nigeria

The vast infrastructure and finely-tuned machinery needed to take the world this far are another asset that will continue to bring benefits as part of the initiative’s legacy. This capacity was best demonstrated in July 2014, when a traveller from Liberia brought the Ebola virus to the sprawling city of Lagos, Nigeria. At that time, the country had put together one of the world’s most innovative eradication campaigns, using cutting-edge technologies to ensure that no child was missed.

Health officials immediately repurposed polio technologies and infrastructures to conduct real-time Ebola case-finding and contact-tracing. World-class epidemiological detective work eventually linked every single one of the country’s 19 confirmed cases back to direct or indirect contact with the July air traveller from Liberia. By October 2014, WHO could declare the Ebola outbreak in Nigeria over.

Source: WHO


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