Member States of the WHO Regional Committee held a side event today to assess implementation of the Polio Eradication and Endgame Strategic Plan 2013–2018. Importation of wild poliovirus from the few remaining polio-endemic countries continues to threaten the Western Pacific Region's polio-free status and worldwide eradication efforts.
The WHO Regional Director for the Western Pacific Dr Shin Young-soo said, "We must press for complete eradication, while the political commitment to end this dreadful disease is strong." Dr Shin heads the Secretariat of the sixty-sixth session of the WHO Regional Committee for the Western Pacific, held this week in Guam, United States of America.
In 2000, the Western Pacific Region, home to more than a quarter of the world's population, became the second WHO region to be certified polio-free. The Region has maintained its polio-free status but, continued vigilance is a must. Since certification, the Region has experienced wild polio virus importations and outbreaks of vaccine-derived polioviruses (VDPVs). Until poliovirus transmission is stopped in polio-endemic countries, polio-free regions remain at risk. In November 2012, an independent oversight body meeting in Beijing, China reconfirmed the Western Pacific Region's polio-free status.
In January 2013, the WHO Executive Board approved the Polio Eradication and Endgame Strategic Plan 2013–2018 developed by the Global Polio Eradication Initiative. This plan requires the removal of all OPVs in the long term, beginning with a switch from trivalent OPV (tOPV) to bivalent OPV (bOPV), facilitated by the introduction of at least one dose of IPV into the routine immunization.
In the Western Pacific Region, 17 countries and areas use an all-OPV schedule in their national immunization programmes. All of these countries have made formal commitments to introduce at least one dose of IPV. In addition, Malaysia and Singapore use a sequential schedule with IPV for the primary series followed by an OPV booster. Malaysia, Tokelau and Tuvalu plan to adopt an all-IPV immunization schedule by the end of 2015. With the recent global supply chain shortages, Mongolia and Viet Nam are expected to introduce IPV in 2016.
The OPV-using countries in the Western Pacific Region have made formal commitments to switch from tOPV to bOPV in April 2016. Fifteen countries and areas have developed and finalized national switch plans by the end of September 2015.
Background
In May 2012, the World Health Assembly, the governing body of WHO, declared the completion of poliovirus eradication to be a "programmatic emergency for global public health".
In response, the Polio Eradication & Endgame Strategic Plan 2013-2018 was developed with four objectives to: detect and interrupt all poliovirus transmission; strengthen immunization systems and withdraw oral polio vaccine (OPV); contain poliovirus and certify interruption of transmission; and plan polio's legacy (ensuring that the investment in polio eradication provides public health dividends for years to come).
The plan stipulates that all OPVs must be removed from both routine programmes and campaigns in phases. The first phase is a switch from the current trivalent oral polio vaccine (tOPV), containing antigens for poliovirus types 1, 2 and 3, to bivalent OPV (bOPV), containing only types 1 and 3. The global switch from tOPV to bOPV is expected to occur in April 2016, and this switch must be globally coordinated. Any use of tOPV after April 2016 could jeopardize polio eradication by generating vaccine-derived polioviruses from the type 2 component of the vaccine.
To prepare for the switch in April 2016, all OPV-using countries must finalize a national plan by September 2015. Timely planning and implementation will increase the probability of a successful removal and disposal of tOPV, minimize tOPV wastage and ensure a world free of circulating vaccine-derived polioviruses type 2.