Africa has been declared free from wild polio by the independent body, the Africa Regional Certification Commission.
Polio usually affects children under five, sometimes leading to irreversible paralysis. Death can occur when breathing muscles are affected.
Twenty-five years ago thousands of children in Africa were paralysed by the virus.
The disease is now only found in Afghanistan and Pakistan.
There is no cure but the polio vaccine protects children for life.
Nigeria is the last African country to be declared free from wild polio, having accounted for more than half of all global cases less than a decade ago.
The vaccination campaign in Nigeria involved a huge effort to reach remote and dangerous places under threat from militant violence and some health workers were killed in the process.
What is polio and has it now been eradicated in Africa?
Polio is a virus which spreads from person to person, usually through contaminated water. It can lead to paralysis by attacking the nervous system.
Two out of three strains of wild polio virus have been eradicated worldwide. On Tuesday, Africa has been declared free of the last remaining strain of wild poliovirus.
More than 95% of Africa’s population has now been immunised. This was one of the conditions that the Africa Regional Certification Commission set before declaring the continent free from wild polio.
Now only the vaccine-derived polio virus remains in Africa with 177 cases being identified this year.
This is a rare form of the virus that mutates from the oral polio vaccine and can then spread to under-immunised communities.
The World Health Organization (WHO) has identified a number of these cases in Nigeria, the Democratic Republic of the Congo, Central African Republic and Angola.
What have the challenges been?
The last communities at risk of polio live in some of the most complicated places to deliver immunisation campaigns.
Nigeria is the last country in Africa to have reported a case of wild polio – in Borno state in Nigeria’s remote north-east, and the epicentre of the Boko Haram insurrection, in 2016.
At the time it was a frustrating set-back as the country had made huge progress and had gone two years without any cases being identified.
Outside Nigeria, the last place to have seen a case of polio was in the Puntland region of Somalia in 2014.
Conflict with the Islamist militant group Boko Haram has made parts of Nigeria particularly difficult to reach, Borno state in particular.
More than two million people have been displaced by the fighting. Frontline workers, 95% of whom were women, managed to navigate areas of conflict like Lake Chad by boat and deliver vaccines to remote communities.
Widespread rumours and misinformation about the vaccine have also slowed down immunisation efforts.
In 2003, Kano and a number of other northern states suspended immunisations following reports by Muslim religious leaders that the vaccine was contaminated with an anti-fertility agent as part of an American plot to make Muslim women infertile. Laboratory tests by Nigerian scientists dismissed the accusations.
Vaccine campaigns resumed the following year, but the rumours persisted. In 2013 nine female polio vaccinators were killed in two shootings thought to be carried out by Boko Haram at health centres in Kano.
It has taken decades to achieve eradication and overcome suspicion around the vaccine.