For a child, receiving a vaccine takes just a moment (and perhaps a few tears). But such moments are crucial for getting children off to a healthy start in life, and for advancing progress on global health and development goals.
Along with Sheikh Mohammed bin Zayed, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the Armed Forces, we attach great importance to the world's first global summit, being held this week in Abu Dhabi, aimed at ensuring that all children have access to the full benefits of vaccines.
Vaccines protect people for a lifetime. They are one of the most cost-effective investments we can make to improve our world. Vaccines have eradicated smallpox, pushed polio to the verge of eradication, and saved millions of children from measles, diphtheria, tetanus and other deadly and disabling diseases. Thanks in large part to the power of vaccines, the number of children dying before the age of five has fallen from 20 million in 1960 to 6.9 million in 2011, despite a large increase in global population.
Disease saps the greatest asset that any country possesses: the energy and talent of its people. This is an especially harsh loss for poor countries seeking to gain a foothold in the global economy.
But when children are healthy, families are freed from the burden of costly medical care, allowing them to spend more on food and education. Healthy children attend school more regularly, are better able to learn, and become more productive adults. New research shows that vaccines improve cognitive development in children, raise labour productivity and contribute to a country's overall economic growth.
Yet more than 22 million children lack access to the basic vaccines that people in high-income countries take for granted. These children live in the poorest and most remote communities, where the risk of disease is highest. A child born in a low-income country is 18 times more likely to die before reaching the age of five than a child in a high-income country.
Ending this inequity is at the heart of history's largest and most successful anti-poverty push - the Millennium Development Goals. The eight MDGs were adopted in the year 2000, when leaders meeting at the United Nations agreed to cut extreme poverty and hunger by half, fight disease, improve water safety and sanitation, expand education and empower girls and women. There have been remarkable gains, but there is still much to do - and fewer than 1,000 days of action left until the 2015 deadline.
Raising global immunisation coverage will speed progress toward the MDGs and generate momentum toward a successful post-2015 development agenda. The World Health Assembly, representing the World Health Organisation's 194 member countries, has endorsed a shared vision - known as the Decade of Vaccines - of a world free from vaccine-preventable diseases, with the full benefits of immunisation reaching all people, regardless of who they are or where they live.
Eradicating polio will be a milestone on our path to realising this vision. With a new, comprehensive plan to be introduced at the summit, the world will have a clear road-map for creating a polio-free world by 2018.
The plan works hand in hand with our overall efforts to raise immunisation coverage against other diseases like measles, pneumonia and rotavirus. Indeed, we are seeing how strong immunisation systems protect our gains against polio and provide a platform for reaching the world's most vulnerable mothers and children with new vaccines and primary health care.
If we are successful, by the end of the decade we will save more than 20 million lives, prevent nearly one billion cases of illness and save almost $12 billion in treatment costs alone. And in the process of freeing people from the burden of disease, we will unlock immeasurable human potential.
The MDGs and the Decade of Vaccines prove that focused global development objectives can make a profound difference. They show the power of partnerships that bring together the United Nations, governments, development agencies, civil society, foundations and the private sector.
Over the next 1,000 days and beyond, our progress will be measured by what we have done to improve the lives of the poorest and most vulnerable members of the human family.
Let us start by recommitting ourselves to realising the shared vision of a world in which all children get a fair start in life with the protection of vaccines. This generation will thank us - and so will many generations to come.
Ban Ki-moon is Secretary-General of the United Nations. Bill Gates is Co-Chair of the Bill & Melinda Gates Foundation
©Project Syndicate 2013