Nigeria has made a vital step towards being declared polio free, after marking a year without a recorded case.
It can now be taken off the list of countries where the disease is endemic, if the World Health Organization (WHO) confirms the results.
Nigeria had struggled to contain polio since some northern states imposed a ban on vaccinations in 2003.
Pakistan and Afghanistan are the only countries to record cases in 2015.
Global health experts are hoping polio can become only the second human infectious disease to be eradicated, after smallpox.
Nigeria will still have to wait a further two years without a recorded case to be certified as polio free.