Africa Declared Free Of Wild Polio Virus

It’s not the virus capturing most of our attention right now, but there was a time when it was polio, not Covid, that struck fear into people’s hearts as they anxiously awaited a vaccine. It’s therefore heartening to hear, as we’re locked in a battle against this new coronavirus, that we’ve been steadily winning in the battle against polio virus for decades. And we just scored another big win.

Four years after the last case of wild polio in Nigeria, the World Health Organization announced today that its African Region, which includes all but seven countries on the continent, is officially free of wild poliovirus. (The other seven African nations—Morocco, Tunisia, Libya, Egypt, Sudan, Somalia, and Djibouti—are included in the WHO’s Eastern Mediterranean Region.)

“This milestone is truly an incredible public health achievement for Rotary members, the African region, and our Global Polio Eradication Initiative (GPEI) partners, and a huge step forward on the road to global polio eradication,” said Dr. Tunji Funsho, chair of Rotary International’s Nigeria National PolioPlus Committee. “The success in eliminating the wild poliovirus throughout the WHO African region is proof that with strong commitment, coordination and perseverance, polio eradication is possible.” 

Wild poliovirus refers to the last remaining strain of polio found in the wild, as opposed to polio infections that result from the oral polio vaccine. No cases of the other two wild poliovirus types (2 and 3) have been reported since 2015. 

The inactivated polio vaccine, given in the U.S. and many other countries that have long been free of polio, cannot cause polio infections. However, the live oral polio vaccine, which is more effective in reducing community spread of the disease, can lead in rare cases to vaccine-derived poliovirus infections in areas with low levels of polio immunization and poor water hygiene. 

There were 369 cases worldwide of vaccine-derived poliovirus in 2019, and there have been 302 cases to date in 2020. Meanwhile, the 9 billion doses of oral polio vaccines administered since 1996 are estimated to have prevented about 1.8 million cases of wild poliovirus in Africa. 

It was no small feat getting the last of wild polio out of Nigeria, especially with the setbacks of vaccinators’ murders in 2013 and Boko Haram terrorism since then.  The country nearly reached polio-free status—conferred four years after the last identified case—two years earlier. But in 2016, four children in Borno, Nigeria became paralyzed by wild polio after two years of no reported cases. 

“The children were from three different locations in Borno State, an area in northeastern Nigeria that was previously inaccessible to health programs, including polio vaccinators, due to unrest,” Dr. Funsho said. 

Those four cases launched a massive response from the Global Polio Eradication Initiative partners: the WHO, Rotary International, the CDC, UNICEF, the Bill & Melinda Gates Foundation, and Gavi, the Vaccine Alliance. The partners sent vaccinators throughout Borno and its bordering states within Nigeria as well as neighboring Niger, Chad, Cameroon, and the Central African Republic.

The effort required healthcare workers to find their way into areas that had previously been inaccessible, including mapping out the islands in Lake Chad and canoeing for hours to reach hundreds of settlements that GPEI had never previously visited, according to Dr. Funsho. 

In addition, GPEI added mobile phone apps to its surveillance tools for tracking and responding to polio cases. “Apps like AVADAR and e-Surve have undoubtedly played a big role in ensuring that we can detect where the poliovirus is hiding in order to respond to outbreaks,” Dr. Funsho said. 

The effort paid off: ridding Nigeria of wild polio means the disease is gone from five out of six WHO regions, equivalent to 90% of the world’s population. Only two countries in the world, Afghanistan and Pakistan, continue to have local transmission of wild polio—which makes continuing immunization efforts more important than ever.

“We must continue vaccinating every last child and strengthen routine immunization to keep immunity levels high so the virus does not return to Africa,” Dr. Funsho said.