By the middle of 2016, progress continued towards each of the Endgame Plan’s four objectives. The world has never been closer to eradicating polio, with fewer cases in fewer areas of fewer countries than at any time in the past. The virus is now more geographically constrained than at any point in history. As the GPEI enters the second half of 2016, it is more important than ever to redouble efforts to eradicate poliovirus in every corner of the globe.
A major milestone for eradication efforts in the last six months took place in April, with one of the biggest globally coordinated projects in the history of vaccines: the withdrawal of the type 2 component of the oral polio vaccine (OPV) through the switch from trivalent oral polio vaccine (tOPV) to bivalent oral polio vaccine (bOPV) in 155 countries and territories. Referring to the OPV switch in her opening address to the sixty-ninth World Health Assembly in May, WHO Director-General Margaret Chan offered her thanks to countries for what she described as a “marvellous feat”. The World Health Assembly saw leaders reiterate their commitment to eradicating polio. Also in May, the G7 leaders committed to continuing global efforts to reach the targets of the Global Vaccine Action Plan and to achieving polio eradication targets and improving children’s health at the annual G7 summit.
Progress in Afghanistan and Pakistan
Progress reported in the second half of 2015 persisted into 2016. Afghanistan and Pakistan continued to be treated as a single epidemiological block, with greater coordination between the two countries to interrupt transmission. In Pakistan and Afghanistan, the interruption of WPV transmission depends on reaching all missed children, filling chronic gaps in strategy implementation and being able to vaccinate children in infected areas that have been difficult to access owing to insecurity.
The first half of 2016 saw steady progress in Pakistan as the number of polio cases continued to decline. Up to July 2016, 19 polio cases were reported compared to 54 in 2015.
The National Emergency Action Plan (NEAP) for the disease was directly overseen by the office of the prime minister. Emergency operations centres at the federal and provincial levels ensured the almost real-time monitoring of activities, the implementation of corrective action, and increased accountability and ownership at all levels. Most importantly, the NEAP focused on identifying chronically missed children and the reasons they were missed, and on implementing area-specific approaches to overcome these challenges.
Despite this improvement, vaccination gaps persisted in Karachi, in the Peshawar-Khyber corridor and in parts of the Quetta block, with evidence of continued transmission.
Progress continued also in Afghanistan in the first half of 2016 as the number of polio cases continued to decline steadily. Polio eradication remained at the top of Afghanistan’s health agenda. Six cases were reported in the first six months of the year, compared to 20 in 2015. In 2015 and 2016, the Government of Afghanistan increased its efforts to accelerate polio eradication in the country amid multiple complex challenges, including increasing conflict and insecurity in many parts of the country. Most areas of Afghanistan stayed polio-free, but WPV continued to circulate in some parts, particularly in Eastern and Southern Regions.
Polio detected in Nigeria
The fragility of progress made in fighting the virus was underscored by the detection of wild poliovirus type 1 (WPV1) in Borno state, Nigeria, in August 2016 (although this falls outside of the reporting period for this status report). This setback came after almost two years without a case of WPV being detected across the African continent. Although this was a sobering development, the GPEI is confident that the global eradication of polio once and for all remains within sight. Genetic sequencing confirmed the virus had been circulating undetected since 2011, underscoring the risks of low-level transmission and subnational surveillance gaps, particularly in inaccessible areas. In response, the Government of Nigeria declared the outbreak a national public health emergency, and a regional Lake Chad subregion outbreak response was immediately launched, within the broader humanitarian emergency response.
Ongoing responses in other areas
In the first six months of 2016, only one country, Lao People’s Democratic Republic, reported cases due to a circulating vaccine-derived poliovirus type 1 (cVDPV1) outbreak. Early in the year it notified a total of three cVDPV1 cases; no cases were reported from the country after 11 January 2016. The second outbreak response assessment in Lao People’s Democratic Republic concluded that the country is on track towards interrupting virus transmission. However, subnational surveillance gaps persisted in other key areas previously affected by confirmed circulating vaccine-derived polioviruses (cVDPV), including in parts of Guinea.
Global vaccine switch from trivalent to bivalent oral polio vaccine
The largest-ever globally coordinated vaccine switch happened in April 2016. From 17 April to 1 May 2016, all countries that used tOPV successfully switched to bOPV through a globally-synchronized replacement. This was the first step in the phased removal of OPVs, which will culminate with the cessation of all OPV use following global certification of eradication. To prepare for the switch to bOPV, all countries had committed to introducing at least one dose of inactivated polio vaccine (IPV) into their routine immunization programmes.
The level of commitment from countries to meet this goal was exceptional.
Containment and certification
In September 2015, the Global Commission for Certification of the Eradication of Poliomyelitis (GCC) declared that WPV2 has been eradicated. No cases of WPV2 have been reported since 1999. Efforts to implement GAPIII, the WHO Global Action Plan to minimize poliovirus facility-associated risk after type-specific eradication of wild polioviruses and sequential cessation of oral polio vaccine use, which was endorsed by the World Health Assembly in May 2015, continued. Containment activities commenced in all six WHO regions, and Member States intensified efforts to identify facilities holding wild or vaccine-derived polioviruses, destroy all poliovirus materials or, where necessary, appropriately contain poliovirus materials in essential poliovirus facilities, with priority given to type 2 poliovirus materials (the strain already eradicated globally).
In the first half of 2016, the acceleration of polio transition planning (formerly known as “legacy planning”) continued, to ensure the functions and assets of the GPEI persist to benefit broader public health efforts even after the successful eradication of the disease. uring this period, the GPEI reached more children than ever before, including children in remote and often insecure areas. The lessons learnt and infrastructure built can continue to reap rewards after eradication.
Financing the Endgame Plan
Donors reiterated their commitment to supporting polio eradication until certification is achieved. However, a further US$ 1.5 billion against the US$ 7.0 billion budget is required to fully implement the Endgame Plan and meet its goal of global certification in 2019.
Looking to the future
Progress in the first half of 2016 was strong and continued to justify cautious optimism; the global vaccine switch constituted a major success for polio eradication efforts on a global scale. Surveillance systems remain essential to monitor and stop outbreaks. The absence of wild poliovirus type 3 (WPV3) since November 2012 sustained confidence that WPV3 transmission has been stopped. Wild poliovirus type 2 (WPV2) was globally certified as eradicated in September 2015, leaving only WPV1. On entering the second half of 2016, the GPEI is shifting focus onto eight key areas:
stopping transmission of WPV in Afghanistan and Pakistan;
stopping the outbreak in Nigeria by fully implementing the outbreak response in the Lake Chad subregion;
rapidly detecting and responding to any type 2 virus;
urgently filling subnational surveillance gaps;
continuing to increase the supply of IPV, including using innovative solutions such as fractional dose IPV;
rapidly mobilizing the additional US$ 1.5 billion budget requirements; and 8. promoting country-led plans for the transitioning of GPEI assets.