This study shows that the nationwide rollout of the polio vaccine in the 1950s didn’t just save lives in the short term—it extended them decades later. By comparing cohorts before and after the vaccine became widely available, Fletcher and Noghanibehambari found that children vaccinated against polio experienced significantly lower mortality in old age. The campaign contributed to over 15% of the observed drop in death rates among these cohorts, translating into meaningful gains in life expectancy. This work highlights the powerful, long-lasting impact of early-life public health interventions—not just in preventing disease, but in extending lives.