Africa wins battle against wild poliovirus, WHO announces; threat of vaccine-derived polio persists

Polio is a highly contagious virus and was endemic around the world until a vaccine was found in the 1950s.

tech2 News Staff August 28, 2020 09:00:52 IST
Africa wins battle against wild poliovirus, WHO announces; threat of vaccine-derived polio persists

On Tuesday, 25 August, the Independent Africa Regional Certification Commission (ARCC) for Polio Eradication and the World Health Organization (WHO) made a joint announcement that the African continent is now free of the wild poliovirus, after decades of work to eradicate it. However, cases of vaccine-derived polio still exist in more than a dozen countries.

The announcement by the ARCC comes after no new cases have been reported in the past four years. Polio had once paralyzed around 75,000 children a year across Africa.

Health authorities see the win as a rare glimmer of good news for Africa amid a raging coronavirus pandemic, an Ebola outbreak in western Congo and the persisting challenges of deadly infections like malaria, HIV and tuberculosis.

Africa wins battle against wild poliovirus WHO announces threat of vaccinederived polio persists

Vaccine-derived polioviruses are rare, but they affect under-immunized populations living in areas with inadequate sanitation and low levels of polio immunization. Image credit: WHO

"This is an incredible and emotional day," Matshidiso Moeti, WHO Africa director said in a statement, simultaneously urging vigilance, with the COVID-19 pandemic threatens vaccination and surveillance efforts.

The World Health Organization says this is just the second time a virus has been eradicated in Africa, after the elimination of smallpox four decades ago.

"Today we come together to rejoice over a historic public health success, the certification of wild poliovirus eradication in the African region," Tedros Adhanom Ghebreyesus, director-general of the World Health Organization and chair of the polio oversight board, said during a live-streamed event. "The end of wild polio in Africa is a great day. Your success is the success of the world. None of us could have done this alone."

Poliomyelitis — the medical term for polio — is a highly infectious, water-borne disease which attacks the spinal cord and causes irreversible paralysis in children. It is typically spread from the faeces of an infected person and picked up via contaminated water or food. There is no treatment or cure for polio, but vaccination can prevent them from becoming infected and breaks the cycle of transmission. Widespread and diligent vaccination efforts eventually eradicate the infection in the wild.

History of polio eradication efforts

The poliovirus is contagious. It was endemic to many parts of the world till a vaccine was invented in the 1950s. Yet, remained out of reach for many poorer countries in Asia and Africa.

In 1988, when the WHO, UNICEF and Rotary launched the worldwide campaign to eradicate the disease, there were 3,50,000 cases globally. In 1996, there were more than 70,000 cases in Africa alone.

Since 1996, eradication efforts "have prevented up to 1.8 million children from crippling life-long paralysis and saved approximately 1,80,000 lives," the UN agency said.

Worldwide eradication campaigns and financial backing (some $19 billion over 30 years) have helped bring the number of polio cases down low enough that only two nations reported new cases; Afghanistan and Pakistan have reported 87 new polio cases in 2020. Vaccination efforts are slow going in these regions due to insurgency and attacks on health workers.

Nigeria's violent tryst with vaccines

In Nigeria's northern Muslim-majority areas, authorities were forced to stop vaccination campaigns in 2003 and 2004 by Islamic extremists. It took a huge effort in tandem with traditional chiefs and religious leaders to convince populations that the vaccine was safe.

"People trust their local traditional leaders who live with them more than the political leaders," said Grema Mundube, a community leader in the town of Monguno, in the far north of Nigeria.

Africa wins battle against wild poliovirus WHO announces threat of vaccinederived polio persists

As part of Mozambique's polio vaccination campaign, mothers take their babies to receive vaccinations at a mobile unit in Molumbo district. Image credit: UNICEF/Claudio Fauvrelle

"Once we spoke to them, and they saw us immunizing our children they gradually accepted the vaccine," he told AFP.

The emergence of the violent Islamist group Boko Haram in 2009 made this vaccine campaign deadly. The group violently opposed the vaccination drives as they considered it a plot to sterilize Muslims. The group had carried out a deadly insurgency for over a decade. Health workers at times had to carry out vaccination drives at the margins of the insurgency, putting their own lives at risk.

For areas controlled entirely by the jihadists, WHO and its partners reportedly intercepted people coming in and out along market and transport routes as in a bid to spread medical information, and recruited "health informants" who could tell them about any polio cases in the area.

"I pay special tribute to the frontline health workers and vaccinators, some of whom lost their lives, for this noble cause," Moeti said. "This historic achievement was only possible thanks to the leadership and commitment of governments, communities, global polio eradication partners and philanthropists."

In 2016, the last few polio cases detected were four Nigerian children in Borno state. This was at the heart of the conflict and over 20 health workers lost their lives.

"At the time, we couldn't reach two-thirds of the children of Borno state — 4,00,000 children couldn't access the vaccine," said Tunji Funsho, a Nigerian doctor and local anti-polio coordinator for Rotary International to AFP.

In some areas that were "partially accessible", vaccination teams worked under the protection of the Nigerian army and local self-defence militias. Local authorities could not be more content with the result, despite the feat taking decades to accomplish.

"Happiness is an understatement. We've been on this marathon for over 30 years," said Funsho. "It's a real achievement, I feel joy and relief at the same time."

Africa still not polio-free

This new declaration doesn’t mean Africa is polio-free. Cases remain of the so-called vaccine-derived poliovirus, which is a rare, mutated form of the weakened-but-live virus that the oral polio vaccine is made from.

Africa wins battle against wild poliovirus WHO announces threat of vaccinederived polio persists

A girl receives two drops of the oral polio vaccine during an immunization campaign in Somalia. Image credit: UNICEF

The mutated poliovirus (from vaccines) is rare, but capable of sparking crippling polio outbreaks that 16 African nations are still experiencing – Angola, Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Ivory Coast, Congo, Ethiopia, Guinea, Ghana, Mali, Niger, Nigeria, Togo and Zambia.

To eradicate the virus completely, over 90 percent of children need to be immunized, typically in mass campaigns involving millions of health workers that would break the social distancing norms needed to prevent COVID-19 from spreading. Health authorities have warned that the coronavirus pandemic has disrupted vaccination work in many countries across Africa, leaving more children vulnerable to polio infection.

Experts have estimated that some 30,000 children are still "inaccessible" – a number considered too low to cause an epidemic to break out. There are concerns that patchy surveillance across the vast continent of 1.3 billion people leaves a possibility that scattered cases of the wild poliovirus still remain, unreported and undetected.

The next step for health organizations addressing polio is ensuring Africa maintains its wild polio-free status, shielded from cases of polio from Pakistan or Afghanistan, and continues vaccinations of children to ensure safety and health of its communities.

With inputs from wires

Updated Date:

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