Polio is a crippling and potentially fatal infectious disease. There is no cure, but there are safe and effective vaccines, which given multiple times can protect a child for life. Exterminating polio requires immunizing every child until transmission stops and the world is free of all forms of poliovirus. Almost 9 billion polio vaccines have been delivered.
The virus that causes polio enters the human body through ingestion of contaminated water or food, multiplies in the gut, and is shed through the feces (stool) into the environment, where it spreads rapidly if sanitation or personal hygiene is poor.
Most people infected with poliovirus have no symptoms, but about one in 200 infected people develop paralytic polio, in which poliovirus invades and destroys the nerve cells that control the arm and leg muscles, leading to acute flaccid paralysis (AFP; limb paralysis).
In the worst cases, poliovirus paralyzes the muscles involved in breathing, which can be fatal unless patients are helped to breathe with an “iron lung” or ventilator. There is no cure for paralytic polio, and although AFP usually lasts less than two weeks, some patients never regain full use of their limbs.
No cure exists for the symptoms, but in the 1950s effective vaccines were developed and have been used around the world since then. This allowed some richer countries to eliminate the disease entirely in the 1960s and 70s.
During the 1970s, polio was endemic in Africa. Billions of dollars are spent each year on polio immunisation and the number of cases has plummeted since the late 1980s. Since 1988, the incidence of polio has been reduced by more than 99 percent, according to WHO.
At the time, more than 350,000 children were paralysed every year, in more than 125 endemic countries. So far, two countries remain which have never stopped endemic transmission of polio: Pakistan and Afghanistan, where there have been in 2015, 41 cases reported (32 in Pakistan, 9 in Afghanistan).
A united world against polio
Leadership from all levels of government across party lines, a historic public-private partnership that raised billions, millions of health workers reaching children across the region from conflict zones to remote areas only accessible by motorbike or helicopter and a culture of continual improvement were all critical to overcoming challenges and bottlenecks.
The Kick Polio Out of Africa Campaign launched in 1996. At the time, wild poliovirus paralyzed an estimated 75,000 children on the continent each year. South African President Mandela led a region-wide mobilization campaign to increase public awareness of the initiative.
In spite of enormous challenges to reach every child with polio vaccine, a promise made in 1996 by African leaders has been a promise kept. Since 1997, leading players from the African Football Confederation have participated in awareness campaigns by spreading the message through a variety of channels.
The initiative includes routine immunization complemented by the National Immunization Days (NIDs), training at the local level, surveillance, and door-to-door campaigns. The initiative must assure functioning systems of cold storage of vaccines and must continue to educate communities about the importance of routine immunization. There must be a strong laboratory network for isolating the 3 types of the virus. NIDs will be scheduled for 1999 in countries with civil conflict. The polio model is useful for other disease eradication campaigns.
Over many years and thanks to the dedicated efforts and sacrifices of health workers, community volunteers, traditional and religious leaders, parents, and country leadership with support from donors, all children, even those in the most remote and insecure areas, have been reached with polio vaccine. Today, about 220 million children across the African region are immunized against polio every year.
A large part of the eradication effort has been through the Global Polio Eradication Initiative (GPEI), which was created in 1988 and is led by national governments and five partners Rotary International, WHO, UNICEF, US Centers for Disease Control and Prevention and the Bill and Melinda Gates Foundation.
The synchronized 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. All children under five years of age in the 13 countries Benin, Cameroon, Central African Republic, Chad, Côte d’Ivoire, Democratic Republic of Congo, Guinea, Liberia, Mali, Mauritania, Niger, Nigeria and Sierra Leone were simultaneously immunized in a coordinated effort to raise childhood immunity to polio across the continent.
In August 2016, four children were paralysed by the disease in security-compromised areas in Borno state, north-eastern Nigeria, widely considered to be the only place on the continent where the virus maintains its grip.
The achievement is the result of Herculean vaccination and surveillance efforts by the international community and health care workers, often working in some of the most dangerous areas of Africa.
The full engagement of political and community leaders at every level right down to the district is considered critical to the success of the campaign. It is only through the full participation of this leadership that all sectors of civil society are mobilized to ensure every child is reached.
The World Health Organization said the campaign has prevented an estimated 1.8 million cases of paralysis in children and saved about 180,000 lives.
Tackling poliovirus threats
Across the region, health workers go village-to-village and door-to-door vaccinating children multiple times and offering health advice and support to the community.
Ending polio requires more than 90 percent of children being immunised, typically in mass campaigns involving millions of health workers – campaigns that would break physical distancing guidelines needed to stop the spread of COVID-19.
Health workers at times carried out vaccinations on the margins of the insecurity, putting their lives at risk. In some African nations, the same health networks developed to eradicate wild polio are now being used to help support the response to the pandemic.
On August 25, 2020, the African Region was officially certified as wild poliovirus-free. With the African region’s certification, five of the six WHO regions representing over 90% of the world’s population. The Centers for Disease Control and Prevention (CDC) has served as the lead implementing partner for U.S. efforts to eradicate polio, playing a pivotal role for three decades in helping African countries and the continent reach this milestone.
The battle of “vaccine-derived polio”
Vaccine-derived polioviruses are rare, but they affect unimmunized and under-immunized populations living in areas with inadequate sanitation and low levels of polio immunization. When children are immunized with the oral polio vaccine, the attenuated vaccine virus replicates in their intestines for a short time to build up the needed immunity and is then excreted in faeces into the environment where it can mutate.
To protect global progress against polio, experts say, we must continue to vaccinate to maintain high population protection against the virus and to prevent polio from travelling to other countries from the two countries (Pakistan and Afghanistan) where wild poliovirus type 1 transmission has not been interrupted.
Africans must also continue to innovate, engage communities and work quickly to stop outbreaks of circulating vaccine derived poliovirus type 2 wherever they occur. If polio immunization coverage remains low in a community and sanitation remains inadequate, the mutated viruses will be transmitted to susceptible populations, leading to emergence of vaccine-derived polioviruses.