Counting lives saved is difficult, but it can show us the great difference some people have made

Scientists can make an enormous difference in the world.

Take the researcher Sarah Gilbert, who has dedicated her career to developing vaccines. Over the last two decades, she has contributed to vaccines against the flu, MERS, Nipah virus, and Rift Valley fever. When she heard about the outbreak in China in January 2020, she began working on a vaccine, just in case. By the end of that year, the vaccine against COVID-19 was approved, saving an estimated 6.3 million lives in the following year alone. Without this effort, we would have faced a much darker reality, marked by lockdowns, overwhelmed health systems, and widespread suffering.

This chart lists many such scientists whose work saved many people’s lives. The estimates are taken from the web publication Science Heroes, where you can find profiles of these scientists.

It’s difficult to estimate the exact difference particular innovations have made, and I take all such estimates with a grain of salt. None of these scientists did their work in isolation; their innovations were achieved thanks to collaborative efforts and the earlier work of other researchers.

Our team spends much of its time counting deaths, but it’s equally important to know the number of lives saved — even though it is harder to estimate and involves much larger uncertainty. It’s inspiring to be reminded that creative, enterprising, and tenacious people can enormously contribute to our lives.