Most people think of polio as something we used to worry about. We want to argue that it is worth a considerable amount of our attention right now.

A quarter of a century ago, the countries of the world set the goal of wiping polio off the planet. Since then, the many partners in this eradication effort have decreased the number of cases by 99 percent. With victory so close, it is only natural to assume that the job is basically done. But in global health, as in many areas of life, the last mile is the hardest mile.

That is why it is absolutely necessary to focus on polio. What happens in the immediate future will determine whether we take the giant leap from 99 percent to 100 percent or whether polio gradually spreads back into countries where it has been eliminated, infecting thousands of children annually for the foreseeable future.

In addition, winning the polio fight will have important consequences beyond ridding the world of this ancient, crippling disease. If we succeed in eradicating polio, we will prove that setting big goals leads to big victories.

Furthermore, we will demonstrate once again that vaccines are the most powerful tool available in public health, giving a boost to the global effort to reach all children with all vaccines.

Millions of children worldwide are currently dying from vaccine-preventable diseases. Getting to zero cases of polio will not only demonstrate the effectiveness of vaccines, it will leave behind an infrastructure that will help us reach more children with more vaccines in the future.

What separates polio from so many other diseases around the world is that the solution is clear. In 1988, when the world set the goal of total eradication, 350,000 children in 125 countries were paralysed by this horrible disease every year.

In 2012, there were 223 reported cases. This progress was made possible by a worldwide effort, including years of leadership from Canada. Finishing the job would make polio only the second disease, after smallpox, to be wiped out.

To meet this challenge, the organisations leading the fight against polio  put together a comprehensive six-year plan that lays out the steps toward eradication. We have never had a complete blueprint that uses all the available data to draw up the endgame.

This plan also marks a significant improvement in our thinking about how to make sure the infrastructure developed for polio can be used to spur progress in other areas of health when the job is done. For example, the plan shows how staying the course on polio can improve routine immunisation systems in many countries.

The plan says exactly how much it will cost to end polio: $5.5 billion over six years. That is a considerable sum, especially in a tight economic environment. But if we don’t follow through on the plan, we will spend significantly more money in the long term trying to control the disease and treating people who get infected.

And while financial support is fundamental to the eradication of polio, we know dollars alone will not get the job done.

Today, polio remains endemic in only three countries: Afghanistan, Nigeria and Pakistan. These are the last battlegrounds for the disease, with a majority of cases in remote and insecure areas.

Despite recent violence, polio vaccinators continue to deliver life-saving vaccines to children, who need them most.

Leaders from the endemic countries are fully committed to ending polio in their countries, and it is the responsibility of the donors, civil society and government leaders to remain diligent in supporting the eradication efforts to ensure that our children, no matter where they live, are protected for generations to come.

This is the time for a final push to end this disease forever. Support now, when it matters most, will show what humanity can do when we understand the stakes. As long as one polio case remains, millions of children continue to be at risk. Together, let’s make polio history.

n    The writers are Canadian Minister of International Cooperation, and the chairman of Microsoft and the co-chair of the Bill and Melinda Gates Foundation respectively. This article has been reduced and reprinted from the Globe and Mail.