Vismita Gupta-Smith, WHO Communications

 Will the world eradicate polio in 2023? How far have we come in our efforts to eradicate polio, and what will it take to get there?

Hello and welcome to Science in 5. I am Vismita Gupta-Smith. We are talking to Aidan O’Leary today. Welcome, Aidan. So this is a very critical year for polio eradication efforts where we are going to try and interrupt all remaining transmission globally. Talk to us about what it will take to get there.

Aidan O’Leary, Director, Polio Eradication, WHO

2023 is the target date to interrupt all remaining polio transmission globally. And we have a very real shot at success. In the two remaining countries, which remain endemic to wild polio virus –  Pakistan and Afghanistan – virus transmission is more geographically restricted than ever before.

In Pakistan, for example, all recent cases are now concentrated in just three districts of a single province, of 170 districts across the country. Even more importantly, the biodiversity of the virus continues to shrink and decline, meaning the individually distinct virus lines that are still active in the country.

In 2020, Pakistan was affected by 11 separate and distinct individual chains of transmission. This was reduced to just 4 in 2021 and to a single chain in 2022. This means that individual virus lines are being successfully knocked out. And we're seeing a very similar situation in Afghanistan, notwithstanding all the humanitarian challenges there with polio virus at an historic low.

So 2023 is very much our year to achieve success. 

Vismita Gupta-Smith, WHO Communications

Aidan, this is WHO's 75th anniversary year. Talk to us about this journey of polio eradication now  that we are in the last mile of this effort. 

Aidan O’Leary, Director, Polio Eradication, WHO

This is clearly a very, very important year for WHO, but for polio virus, it's been with us since ancient Egyptian times. At the time of WHO's formation, we didn't even have a polio vaccine. And hundreds of thousands of children were at risk and were paralyzed all over the world as a result of this. 

During the 1950s, a polio vaccine was developed and vaccinations started in earnest. 

In the 1970s, WHO established its EPI program with a view to effectively and efficiently delivering vaccines, particularly to those in greatest and most acute need.

In the 1980s, the Global Polio Eradication Initiative was established bringing together key partners – WHO with UNICEF, with Rotary International, with the United States Center for Disease Control,  with the Bill and Melinda Gates Foundation, and more recently with GAVI, all with a view to bringing this disease to an end. At that time, there were 365,000 cases across 125 countries.

Today, we have just a handful of cases in just two. Very near, but zero is zero. We really need to finish the job.

Vismita Gupta-Smith, WHO Communications

So, Aidan, in many parts of the world, people have forgotten just how debilitating polio is. And that's mainly because they haven't seen polio in their part of the world. But as we know, the risk remains as long as the virus remains in any part of the world. So talk to us about what it will take to get rid of this disease, to eradicate polio once and for all.

Aidan O’Leary, Director, Polio Eradication, WHO

Very much like COVID-19. As long as we have polio transmission anywhere, potentially everywhere is at risk. And we saw this in a very real way in 2022 when we received reports of detections in London and New York.

So what do we need to do to finish the job? We need to have an absolute, unrelenting focus on what we consider to be the most consequential geographies. These are seven subnational areas around the world where the bulk of new cases are now occurring. These include eastern Afghanistan, the southern part of Khyber Pakhtunkhwa province in Pakistan, south-central Somalia, northern Yemen, eastern DRC, northwestern Nigeria and the Tete province and its hinterland in northern Mozambique. 

Each of these areas are affected by a combination of inaccessibility, insecurity and a range of protracted and complex humanitarian emergencies. The work that we do is not just about bringing polio drops to under immunized children, but it's also working with other partners to really make sure we bring as broad a range of services and supports to these communities who are most at need. 

We are ultimately working in some of the most difficult and underserved areas in the world, and our success there will dictate whether or not we finish the job once and for all.

Vismita Gupta-Smith, WHO Communications 

Thank you Aidan. That was Science in 5 today. Until next time, then stay safe, stay healthy, and stick with science.