Health experts say challenges remain in eradicating polio in international conflict zones, despite impressive gains seen in parts of Africa.
The United States Centers for Disease Control and Prevention has released a report saying no cases of wild poliovirus have been recorded on the continent since August.
It credits successful vaccination efforts in Nigeria for the result.
The only other two countries where polio is still endemic are Afghanistan and Pakistan, although cases are present elsewhere.
Professor Michael Toole is the Deputy Director of Australia's largest virology and communicable disease research centre - the Burnet Institute.
He is speaking with Brianna Roberts.
(Click on the audio tab above to hear the full interview)
