Vaccination is one of the true wonders of humanity, having saved more lives than any other medical invention and providing population-level control of diseases that once ran rampant. Yet, we often fail to appreciate how fundamentally they have changed human life for the better.

At the turn of the last century, infectious diseases caused more than one-third of all deaths in the U.S., killing a greater proportion of people than cancer and heart disease do now. Today, vaccines have made common diseases like diphtheria, typhoid, measles, and whooping cough virtually extinct. Every year through the 20th century, they made more than a million Americans sick. Today, that number has dropped by 98 percent.

The picture is even more dramatic when we look at the poorer parts of the world. Smallpox was one of the world’s most serious infectious diseases, killing indiscriminately for millennia before being finally eradicated in 1977 thanks to a vaccine. It killed some 300 million people over the 20th century, and without the vaccine, just this one disease might still kill 5 million people each year.

Just measuring the currently dangerous infectious diseases, global vaccinations are estimated to save at least 3.8 million lives every year.

And yet, millions of children in the poorer parts of the world go without vaccines every year. This situation was exacerbated by the COVID pandemic that strained health systems and caused 25 million children to miss out on some or all of their vaccinations in 2021. That was 5.9 million more than in 2019 and the highest number since 2009.

Unfortunately, recession, inflation, and many other global challenges caused us to lose focus on the huge potential that vaccines offer.

Global leaders worldwide promised in 2015 to dramatically reduce child deaths by 2030 as part of the Sustainable Development Goals (SDGs). This can only be achieved if we ensure that all vaccine-preventable diseases are controlled.

Unfortunately, there are far too many different promises in the SDGs—169 targets. There is little difference between having 169 priorities and having none. The SDGs have placed core targets such as increased vaccination, eradicating infant mortality, and providing basic education on the same footing as well-intentioned but more peripheral targets like boosting recycling and promoting lifestyles in harmony with nature.

Because the SDGs promise too much, we are failing to achieve any of the promises. This year marks halftime for the SDGs, yet we are nowhere near halfway. On the current trajectory (and not including the backsliding during COVID), we will achieve the SDG promise on vaccines more than half a century late.

We need to identify and prioritize our most crucial goals. My think tank, the Copenhagen Consensus, together with several Nobel laureates and more than a hundred leading economists, has done exactly that: We have identified where each dollar can make the largest impact.

Researchers from Johns Hopkins University and the International Vaccine Access Center (IVAC) have documented both the costs and the benefits of increasing global investment in vaccinations. If we continue with our current level of spending, we will continue to save 3.8 million lives from avoidable diseases between now and 2030.

But things would get even better if we were to increase that coverage just slightly, nudging it upwards as has happened consistently over the past decades. Over the next eight years, from 2023 to 2030, we could save an additional 4.1 million lives.

This would have real costs. The costs climb as we expand vaccination campaigns to harder-to-reach places and families who have so far not engaged with vaccination campaigns. It may be necessary to copy the example of India, which uses food incentives and vaccination ‘camps’ to ensure greater coverage.

Yet, the additional financial cost will still be a relatively modest $1.5 billion extra per year, along with about $200 million in additional time costs. Saving half a million lives each year makes this an incredible opportunity. Using standard economic evaluations across time and considering that avoided impacts closer to now are more important, such a benefit is worth about $170 billion annually.

That means that each dollar spent will generate $101 of social benefits. Achieving a 100-to-1 value for money is an absolutely phenomenal return on a policy to increase global vaccination.

Of all the hundreds of promises the world has made in the SDGs—most of which will never be delivered—a few stand out for their incredible effectiveness. Increased vaccination is clearly one of these policies. If we want to achieve maximal good for the world, we must step up and ensure that resources are allocated to increase vaccinations.