Lagos - Nigeria on Sunday celebrated two years without a new case of polio, in a major stride towards Africa being declared free of the devastating disease.
If no new case is reported by July 2017, Nigeria will be certified free of the virus, which mainly affects children under five and can leave its victims crippled or dead.
As recently as 2012, Nigeria seemed to be losing the battle against polio, recording more than half of all global cases.
But these days the disease is only endemic in Afghanistan and Pakistan.
Nigeria has not seen a case of "wild" polio - contracted person-to-person or through contaminated water - since July 24, 2014, when a child was left paralysed in the impoverished northern state of Kano.
Nigerian President Muhammadu Buhari on Sunday hailed the progress towards wiping out polio, but said more needed to be done keep up the momentum.
"The next major milestone for us as a country is the certification of polio-free status in 2017 by the World Health Organization," he said in a statement.
A sporadic case occurred in August 2014 in Somalia but Nigeria is the last African country where polio was endemic.
"As long as a single child remains infected, children in all countries are at risk of contracting polio," the WHO says on its website.
"Failure to eradicate polio from these last remaining strongholds could result in as many as 200 000 new cases every year, within 10 years, all over the world."- Suspicion over vaccines -
Nigeria had struggled to contain the virus after some northern states imposed a ban on vaccinations in 2003.
Immunisation teams were attacked and even killed as rumours spread about vaccine safety - a phenonemon also seen in Pakistan, where suspicions grew after the CIA ran a fake vaccine drive to help track down Al-Qaeda chief Osama Bin Laden in 2011.
In northern Nigeria, immunisation bans followed allegations by some state governors and religious leaders that vaccines were contaminated by Western powers to spread sterility and HIV among Muslims.
Also read: End of polio in sight as Nigeria celebrates one year polio-free
Independent tests ordered by the government in 2004 declared that the vaccines were safe, but hostility to vaccination drives has remained in some areas.
Boko Haram's bloody six-year Islamist insurgency has also created major security issues for efforts to vaccinate children in the north.
Health Minister Isaac Adewole said the government would get "people out of their comfort zones to further enhance the quality of polio campaigns, reach children in difficult areas and continue to improve routine immunisation."
Buhari meanwhile pledged to work with international partners "to ensure that this disease is wiped off the face of the earth for good".
Nigeria has budgeted 12.6 billion naira ($42.5 million, 38.8 million euros) in 2016 for vaccinations and other programmes to combat childhood diseases such as polio, yellow fever and measles, he added.
Modibo Kassogue, immunisation manager in Nigeria for UNICEF, told AFP that funding was crucial.
"They must also improve monitoring, increase levels of routine immunisation and strengthen the overall health system to prevent the return of polio," he said.
And he said plenty needed to be done in Nigeria to stop children dying of other diseases.
Treatable infectious diseases such as malaria, pneumonia, diarrhoea, measles and HIV/AIDS account for more than 70 per cent of the estimated one million under-five deaths in Nigeria every year, according to UNICEF.
"In Nigeria, one child out of every 13 born dies before reaching age one, and one in every eight does not survive till their fifth birthday," Kassogue said.