A Polio-Free World is Within Our Grasp, but WHO Says There is Still Much to Be Done

Over the course of the last year, important progress has been made toward polio eradication. World Polio Day on October 24 is an opportunity to celebrate how far we have come – and to prepare for the year ahead. The World Health Organization (WHO) is continuing its Global Polio Eradication Initiative to end polio once and for all.

Afghanistan and Pakistan, the world’s last two remaining polio-endemic countries, have an extraordinary opportunity to help the world over the finish line for polio eradication. To stop polio, these two countries must make coordinated efforts to stop the virus for good. It is by reaching those missed children repeatedly with polio vaccines that Afghanistan and Pakistan will stop transmission of the virus in its remaining hiding places.

Pakistan made important progress toward stopping polio this year. However, too many children in key high-risk areas of the country are still being missed by vaccinators and left unprotected against the virus. The country must continue to engage communities, train and protect frontline health workers, and go the extra distance to reach children with vaccines to accelerate their progress into the next year.

Afghanistan is making changes to its program in order to better reach children with vaccines in the midst of a shifting security landscape. Large swathes of the country remain polio-free, but progress is fragile. The programme in Afghanistan is working hard to negotiate access to children in all areas of the country; because while children anywhere remain unprotected, children everywhere vulnerable.

Both Afghanistan and Pakistan have established national emergency action plans and are working through emergency operations approaches, and these will be crucial in ensuring that, as the high season comes to an end, the most vulnerable children are protected against polio, that surveillance is strengthened and that the response is well coordinated.

In September 2015, WHO removed Nigeria from the list of polio endemic countries after a year with no cases of wild poliovirus. Soon after, a year with no reported wild polio cases across the entire African continent was confirmed. This is great news, but WHO says there is still much to do to turn this delicate progress into concrete gains. Vaccinating every child, improving surveillance, strengthening routine immunization systems and maintaining the commitments of governments and communities are keys to keeping Africa polio free.

The outbreaks of wild poliovirus that occurred in the Middle East, Central Africa and the Horn of Africa in 2013 seem to have been brought to an end, but much work still needs to be done to ensure that the virus really has gone from vulnerable countries and to prevent it from returning.

There remains a serious risk that some children are not being reached regularly by vaccination teams in areas left vulnerable by insecurity, weak health systems or population movements. That is why the GPEI continues to work on strengthening the basic delivery of immunization services, to supplement immunization wherever and whenever possible with campaigns, using the most potent tool to stop polio outbreaks – oral polio vaccine – and being very thorough in finding and vaccinating children who are missed for any reason.

The same strategies that are used to stop wild polio are used to respond to outbreaks of vaccine derived poliovirus. Several cVDPV outbreaks in 2014 and 2015 demonstrate the importance of increasing immunization coverage and improving surveillance. In very rare cases, when levels of vaccination are low, the attenuated virus in the oral polio vaccine can circulate between unprotected people, and over time can mutate into a strain that can cause paralysis. Currently, 156 countries and territories use trivalent OPV (tOPV) to vaccinate children against polio in their routine immunization programmes. This vaccine protects against all three poliovirus serotypes (1, 2 and 3). The weakened type 2 strain of attenuated poliovirus in tOPV is no longer needed to protect children from wild polio because it has been declared eradicated, and yet the type 2 component of OPV causes over 90% of cases of cVDPVs. To protect children from the very rare risk of cVDPV, OPV will be removed in a phased manner over the next few years. The first step is to replace tOPV with bivalent OPV (bOPV), which doesn’t contain the type 2 component.

Maintaining and improving surveillance systems is critical to ensuring that any virus is rapidly found so it can be responded to quickly and effectively; surveillance programs are especially crucial in the years following the last detected case of polio in order to be confident that polio transmission has been stopped. Top priorities for 2015 and 2016 include training local health workers and influential members of communities on AFP surveillance, regularly examining the quality of surveillance and expanding stool sampling and environmental sampling amongst high-risk populations.

Once polio is eradicated, laboratories and polio vaccine production sites handling or storing poliovirus must minimize the risk of reintroducing poliovirus into the community. In the coming years, all countries must either destroy poliovirus materials or put in place containment measures to ensure that the risk of reintroduction is minimised.

The knowledge, skills and infrastructure built up over three decades working to end polio are helping us make dramatic progress in children’s health – not only by reducing the number of children paralyzed by polio more than 99  percent, but also by decreasing the number of children dying from preventable diseases. Efforts to stop polio have helped mobilize and train millions of health workers, mapped and brought health interventions to chronically missed communities and bolstered countries’ ability to monitor diseases and quickly respond to outbreaks. The programme must ensure that the assets built by the polio programme continue to benefit the world’s most vulnerable children after the disease is eradicated. This planning will not only benefit these countries’ most vulnerable children; it will keep future generations of children everywhere free from this debilitating disease, and reduce the number of children dying from preventable diseases.

Source: WHO