World Polio Day: Two of Three Viruses Successfully Eradicated
Tue, April 20, 2021

World Polio Day: Two of Three Viruses Successfully Eradicated

WHO announced the eradication of wild poliovirus type 3 worldwide / Photo Credit: Shutterstock


After decades of immunization efforts, two strains of wild polioviruses are now officially eradicated.

On World Polio Day, the World Health Organization made a historic announcement saying that wild poliovirus type 3 (WPV3) has been eradicated worldwide. It is a "historic achievement for humanity," as it comes after the eradication of smallpox and wild poliovirus type 2.

WHO Director-General Tedros Adhanom Ghebreyesus, who is also the Chair of the Global Polio Eradication Initiative (GPEI) Polio Oversight Board, dubbed the second polio eradication as a milestone for global health. He said the help, commitment, and innovation from partners and countries helped in cutting down the strains until only one remained.

"We remain fully committed to ensuring that all necessary resources are made available to eradicate all poliovirus strains," Ghebreyesus said in a statement. "We urge all our other stakeholders and partners to also stay the course until final success is achieved."



Decades of labor

The GPEI, a public-private partnership led by national governments, has been working alongside the WHO, UNICEF, CDC, Rotary International, and the Bill & Melinda Gates Foundation for the last 31 years in the effort to eliminate polio. In those years, they have reduced polio cases by over 99.9 percent globally.

Rotary International is the top private-sector contributor to the initiative. According to Forbes, Rotary and its over one million members alone contributed $2 billion and countless volunteer hours in immunizing 2.5 billion children—which helped 122 countries eradicate polio.

"The polio eradication efforts have saved the world more than US$27 billion in health costs since 1988," the WHO said in a statement. "A sustained polio-free world will generate further US$14 billion in savings by 2050, compared to the cost countries would incur for controlling the virus indefinitely."

But before that was achieved, the disease killed half a million a year during its peak in the mid-20th century. The launch of the eradication program in 1988 faced over 350,000 polio cases in 125 countries, as per data on Vox. Vox is an American news and opinion website noted for its concept of explanatory journalism.

With the eradication of type 2 and 3 polioviruses, humanity is moving closer to achieving a polio-free world. But it won't be easy to get the 94 cases of type 1 polio down to zero—especially with the remaining obstacles in place.



Facing the remaining challenges

The remaining poliovirus type 1 strain is in circulation in two countries: Afghanistan and Pakistan, where ongoing political conflicts challenge the eradication efforts.

Afghanistan made great improvements in polio eradication as it recorded merely 16 cases this year. However, the same can't be said to Pakistan, which Forbes says increased polio cases to 66 from the 12 cases in 2018 and eight in 2017.

Cases of vaccine-derived type 2 virus cropping up in Africa, Myanmar, and the Philippines are also a concern in the initiative. These types of viruses are caused by a mutated version of the poliovirus presented by a vaccine for the already phased-out type 2 oral vaccine. Although they are rare, these cases can emerge and spread out particularly in places where vaccination rates are low such as conflict zones.

Such cases occur when a person swallows the oral vaccine containing a live, weakened virus. According to Vox, the virus can live in a person's gut and pass it to another person—all while developing mutations.

"When it circulates for a long time among too many poorly vaccinated or unvaccinated children, this is how it is allowed to mutate and become virulent again," Michel Zaffran, director of the polio eradication program at the WHO, told the American news site.

The Polio Global Eradication Initiative phased out this vaccine and made a switch to a safer oral one in 2016, but not before the emergence of outbreaks today.


The eradication of WPV3 sets a milestone of achievement / Photo Credit: Shutterstock


No stopping now

The eradication of WPV3 is an achievement that "should reinvigorate the eradication process and provides motivation," to completely eradicate all polio strains—including the WPV1.

"We cannot stop our efforts now: we must eradicate all remaining strains of all polioviruses," David Salisbury, chair of the independent Global Commission for the Certification of Poliomyelitis Eradication, said in a celebration event at the WHO Headquarters in Geneva.

Salisbury added that the circulation of vaccine-derived type 2 virus "must urgently be stopped."

Even with the remaining challenges, the polio program has proven that it can beat the odds. This was shown in how it was able to eradicate the disease in India, where polio was paralyzing 500 to 1,000 children per day in the 1990s.

"The wrenching spectacle of child polio victims begging in that nation’s streets, with their twiglike legs folded beneath them, is now history," award-winning writer Richard Conniff stated in the Scientific American science magazine.

People must remain vigilant against diseases in order to maintain immunization levels. This, so that decades of immunization and eradication won't go to waste and that the world would be able to meet its goal of a polio-free society—one where no human is crippled by a preventable disease.