As the world prepares to celebrate Africa’s certification as being free of wild polio, we must be mindful of the ongoing challenges we will face as we seek to achieve and sustain polio eradication, such as disruption to polio campaigns due to COVID-19, the rise of polio cases in other parts of the world, and the continuation of a different form of polio in the region (vaccine-derived polio).
Today is, undoubtedly, a moment to celebrate: the remarkable progress made on polio has been one of the great success stories of the modern era. This celebration has been made possible by the tireless efforts of dedicated health workers and over 20 million volunteers. Since the inception of the Global Polio Eradication Initiative (GPEI) in 1988, polio cases have decreased by over 99%, which has resulted in 18 million people walking today who may otherwise have been paralysed.
The Democratic Republic of Congo (DRC) covers a space the size of western Europe, with mountainous terrain, dense forest, and a network of small roads, making reaching rural communities with vaccines and preventing polio transmission a challenging task. However, the relentless work of thousands of volunteers using innovative methods to reach children in remote locations resulted in over 250 million children being vaccinated and the DRC being certified wild poliovirus free in 2015.
While today’s certification of Africa becoming wild poliovirus free is a momentous achievement, we must be mindful of the fact that the continent still has cases of what is known as Circulating Vaccine Derived Poliovirus (cVDP). This form of polio occurs in rare circumstances in which the strain of polio in the oral polio vaccine mutates, causing it to circulate within communities with low immunisation coverage. We have seen increases in cVDP cases in western and central Africa. The DRC, although officially free from wild poliovirus for five years, is now responding to outbreaks of cVDP. cVDP is potent in areas of low poliovirus immunity and poor sanitation, which means that countries with weak or overburdened health systems are most susceptible. This acts as a reminder of the need for continued political will to achieve polio eradication, and the need for integrated approaches to achieving primary health care that support and strengthen countries’ health systems.
The more commonly known, Wild Polio Virus (WPV1) is endemic in only two countries, Pakistan and Afghanistan. However, cases of WPV1 are increasing at extremely concerning rates. 70 WPV1 cases reported between January and June 2020, with only 57 cases during the same period in 2019, and only 33 reported cases in the whole of 2018. The WHO has predicted that a failure to sustain polio eradication could result in a resurgence of polio leading to 200,000 new cases per year within 10 years. This extremely concerning outcome is possible until we are able to protect every child everywhere, regardless of where they live.
The GPEI supports vital disease surveillance, vaccine supply and logistics networks that play a foundational role in countries’ entire immunisation systems. The impact on countries’ health systems, however, is wider. The GPEI’s response to the COVID-19 pandemic is indicative of just how critical the organisation continues to be in the strengthening and providing much-needed health infrastructure, with GPEI staff and assets being deployed in countries with some of the world’s most fragile health systems to respond immediately to the pandemic. However, this comes at a cost to polio eradication efforts, with resources being diverted towards the pandemic response, and fear of health workers spreading COVID-19 having initially halted polio campaigns. In the two remaining polio endemic countries, Afghanistan and Pakistan, it is estimated that 50 million children missed their polio vaccines as result of disruption. It is therefore vital that the GPEI, along with all relevant partners, including Gavi, the Vaccine Alliance, intensifies immunisation catch-up activities, and works collaboratively to avoid a resurgence of polio.
In the longer term, the global health community needs to adequately plan for the decline of GPEI resources and what this will mean for achieving and sustaining polio eradication, in addition to the general role the GPEI plays in countries immunisation and health systems. It is a process that requires meticulous preparation, continued political will, and accountability on the part of domestic governments and global agencies.
The achievements in polio to date must be celebrated; however, we face significant challenges to the progress we have made. The simple fact remains that if one child remains infected, children in all countries are still at risk of contracting polio.