The HPV vaccine

How it saves lives

The vaccine trains the immune system to recognize human papillomavirus, the infection responsible for almost all cervical cancer, before it is ever encountered. Given to adolescents, typically before they become sexually active, it prevents the persistent infections that would otherwise, years or decades later, develop into precancerous changes and then cancer. Because the effect takes years to show up in cancer statistics, it took more than a decade after vaccination began for the first hard mortality data to arrive.

The story

England began vaccinating 12 and 13 year old girls against HPV in 2008. It took until 2021 for a national study to show the vaccine was preventing cervical cancer itself, not just the precancerous cell changes doctors already knew it stopped: 448 fewer cancers, and 17,235 fewer precancers, than would otherwise have been expected in vaccinated women. A second study, following those same women into their twenties, found something starker still. Among women aged 20 to 24 between 2020 and 2024, almost all of them vaccinated at 12 or 13, not one died of cervical cancer, against roughly 23 deaths historical rates would have predicted. Across all vaccinated cohorts in England, the vaccine is associated with around 199 fewer cervical cancer deaths through the end of 2024.