(CNN) — Polio has been declared eradicated from Africa, the World Health Organization.
“Today we come together to rejoice in a historic public health success, the certification of wild poliovirus eradication in the African region,” said Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, during a livestreamed event.
“The end of wild polio in Africa is a great day,” said Tedros, who is also the chair of the Polio Oversight Board. “His success is the success of the world. None of us could have done this alone.”
The polio was once a common virus. In some young children it can affect the nerves and cause muscle weakness or paralysis. There is no treatment or cure, but getting vaccinated can prevent infection.
Governments and non-profit organizations have worked since 1996 to try to eradicate the virus from the African continent with sustained vaccination campaigns. Nearly 9 billion polio vaccines have been delivered, according to Tedros.
A large part of the eradication effort has been carried out through Global Polio Eradication Initiative (GPEI), which was created in 1988 and is led by national governments and five partners: Rotary International, WHO, UNICEF, the US Centers for Disease Control and Prevention and the Foundation Bill and Melinda Gates.
US Secretary of Health and Human Services Alex Azar, US Centers for Disease Control and Prevention Director Dr. Robert Redfield, and Co-Chairman of the Bill & Melinda Foundation Gates, Bill Gates congratulated Africa on polio eradication during the milestone certification event on Tuesday.
“Today is a historic day for global health and a cause for celebration for all who work to improve the health of Africans,” Azar said in a pre-recorded message. “Congratulations to everyone who helped make it possible.”
Officials wanted to make sure polio really did go away and have waited four years since the last case of the wild virus was diagnosed.
Rose Gana Fomban Leke, president of the African Regional Commission for Certification of Polio Eradication, told CNN that the decision to declare the region free of the virus came after many years of surveillance, immunization and laboratory analysis of the poliomyelitis in the 47 member states of the region on the continent.
“The work has continued for years and now we can see the results. It is a huge milestone. I am sure I can say that in the region, for the last four years, we have not seen a single poliovirus,” she said.
According to a WHO statement, “The last case of wild poliovirus in the region was detected in 2016 in Nigeria. Since 1996, polio eradication efforts have prevented up to 1.8 million children from lifelong paralysis and saved approximately 180,000 lives.
This does not mean that no child will develop symptoms of polio. The weakened virus used to make the oral vaccine can sometimes survive in unimmunized populations, and if it circulates long enough, it can change back into a dangerous form. It is called circulating vaccine-derived poliovirus. The WHO says that 16 African countries are currently battling outbreaks of this vaccine-derived strain.
“The small risk of circulating vaccine-derived poliovirus pales in comparison to the enormous public health benefits associated with oral polio vaccine,” says WHO on your website.
“Each year, hundreds of thousands of cases due to wild poliovirus are prevented. More than 10 million cases have been prevented since large-scale administration of the oral polio vaccine began 20 years ago.”
That’s why children in developing countries get two doses of the vaccine: the oral vaccine, which is given in easy-to-administer drops, and an injection, which is made with a completely inactivated poliovirus that cannot be reactivate. Children in developed countries only get the vaccine, but they need four doses to be fully protected.
“In the past, circulating vaccine-derived polioviruses were quickly stopped with two or three rounds of high-quality immunization campaigns. The solution is the same for every polio outbreak: immunize all children multiple times with the oral vaccine to stop the transmission of polio, regardless of the origin of the virus,” the WHO said.
The last region to eradicate wild polio was Southeast Asia. Polio has been eradicated in the Americas, Europe, most of Australasia, and now in Africa. Wild strains of polio now only circulate in two countries: Afghanistan and Pakistan.
“Wild poliovirus cases have decreased by more than 99% since 1988, from an estimated 350,000 cases in more than 125 endemic countries at the time, to 175 reported cases in 2019,” the WHO noted.
Bill Gates, founder of Microsoft and co-chairman of the Bill & Melinda Gates Foundation, called it a “historical milestone and public health triumph for Africa.”
But he warned that now more than ever it is important to protect the advances made. Wild polio is still present in Pakistan and Afghanistan, and until it’s gone everywhere, it may still come back, she said.
Redfield, of the CDC in the US, also stressed that there is still work to be done. He said that each country must continue to vaccinate to maintain high levels of protection against vaccination.
“This is Africa’s time to celebrate and savor, and I want you to know that the CDC is with you today, until the day polio is finally eradicated,” Redfield said in a prerecorded interview.
“They have shown how much can be accomplished when determination, partnership and resources come together, no matter the circumstances,” he said.