“We are deeply saddened by the news that two Nigerian children have been paralyzed by polio,” said Dr. Matshidiso Moeti, World Health Organization (WHO) Regional Director for Africa, in a news release.

“The overriding priority now is to rapidly immunize all children around the affected area and ensure that no other children succumb to this terrible disease,” she added.

The release added that the Government Nigeria is collaborating with WHO and other partners of the Global Polio Eradication Initiative to respond urgently and to prevent more children from being paralyzed.

The steps include conducting large-scale immunization campaigns and strengthening surveillance systems that help catch the virus early. These activities are also being strengthened in neighbouring countries, according to the agency.

“We are confident that with a swift response and strong collaboration with the Nigerian Government, we can soon rid the country of polio once and for all,” said Dr. Michel Zaffran, Director of polio eradication at WHO headquarters in Geneva.

As recently as 2012, the west African country accounted for more than half of all the polio cases in the world, however since then, Nigeria has made significant strides to stop this dangerous disease. The two new cases are the first ones to be reported after more than two years without any new wild poliovirus cases in the country.

WHO added that the two new cases have underscored that reaching the children in affected areas requires vaccinating populations that move in and out of inaccessible areas and areas plagued by violence due to the Boko Haram insurgency, particularly in Nigeria’s north-east.

Furthermore, agencies have to work with local-level groups and organizations, such as religious institutions and community based organizations, to negotiate access for vaccination tea

“This is an important reminder that the world cannot afford to be complacent as we are on the brink of polio eradication – we will only be done when the entire world has been certified polio-free,” added Dr. Zaffran.

The release also noted that the world is very close to reaching the goal of polio eradication. Only 21 wild polio cases have been reported so far in 2016, compared to 34 cases at the same point last year. Only two other countries are reporting polio: Pakistan and Afghanistan. Four out of the six WHO Regions of the world have been certified polio-free, and only one of the three types of wild poliovirus is still circulating in the world (type 1).