The two of us are roughly the same age but we grew up in very different parts of the world. One of us had the luxury of never giving polio a second thought. The other saw his best friend paralyzed by the disease and, some years later, killed by a car as he struggled to cross the street.

It’s a tragic story of the inequities that separate rich countries like the United States from developing countries such as Nigeria. But it's also a hopeful story as progress on polio eradication is made.

In less than a quarter century, the number of children paralyzed by polio has dropped spectacularly — from 350,000 cases annually to just 650 last year. In 1988, there were 125 countries where polio was endemic. Today, there are just three - Nigeria, Pakistan and Afghanistan.

Earlier this year, India was removed from the list of polio-endemic countries. Just two years ago, India — a subcontinent with a population of more than 1 billion — was thought to be the last place on earth where polio would be eliminated.

India’s success proves that polio is a disease that can be defeated in the most challenging circumstances, and for the most part has been. But finishing the job in a remaining few pockets in Nigeria, Pakistan and Afghanistan will take a stronger commitment.

We are at a critical moment in the effort to create a polio-free world: Anything short of complete eradication means we give up on the promise of providing all children, no matter where they live, the benefit of living a life free of this debilitating disease. It also means every year tens of thousands of children — not just in the currently endemic countries but also children in countries that have been polio-free for years — run the risk of getting paralyzed from polio.

The reality is that until the remaining three endemic countries eradicate polio, the virus could make a comeback anywhere. As recent outbreaks in China and Tajikistan have shown, polio knows no borders.

We learned from India’s experience that stopping polio transmission requires a strong commitment by political and community leaders, well-managed and high-quality vaccination programs tailor-made to local circumstances, and adequate financial resources.

The three countries where polio is still endemic are applying these lessons. At the highest levels of government, there is a deep and unwavering commitment. To address unique local conditions, Afghanistan and Pakistan have established permanent polio teams to serve provinces where security conditions have made it difficult for volunteer teams to reach children with vaccines. In Nigeria, satellite technology is being used to help ensure every community is reached.

We need to do all we can to support these kinds of efforts and ensure that leaders at all levels are accountable for getting the job done.

Follow-through of another kind is just as important. The global partnership that has worked so successfully to eradicate polio is nearly $1 billion short of the funds necessary to fully implement the campaign through 2013. Already, the funding shortage has forced cancellation or scaling back of essential vaccination activities in 24 high-risk countries.

This is where governments and other donors can make a key difference — continuing to support the level of funding necessary to sustain the eradication effort. The lagging economy is putting extra pressure on donors, but inaction will not only lead to terrible human suffering; it will also carry a far greater economic price tag than continuing to invest now.

In fact, a successful eradication effort will result in benefits of up to $50 billion by 2035 in the world’s poorest countries, according to world health groups. The world’s investment in polio eradication is also paying dividends by laying the foundation for delivery of other cost-effective health services—including vaccines for other preventable diseases.

Last week, health ministers representing nearly 200 countries underscored their strong belief in the effectiveness of vaccines and their importance of protecting all the world’s children by passing two resolutions. One declared polio eradication a worldwide health emergency. The other endorsed a global plan to ensure that all children — not just those in wealthy countries — have access to vaccines that prevent diseases.

As public health practitioners and as parents, we believe that every child, no matter whether they were born in a U.S. hospital or a hut in Nigeria, deserve to be protected from this preventable disease. And we believe that because eradicating polio is something that benefits us all, we all share in the responsibility to make that happen.