The human papillomavirus, or HPV, vaccine is cutting cases of cervical cancer by nearly 90%, the first real-world data shows.
Cancer Research UK described the findings as "historic", and said it showed the vaccine was saving lives.
Nearly all cervical cancers are caused by viruses, and the hope is vaccination could almost eliminate the disease.
The researchers said the success meant those who were vaccinated may need far fewer cervical smear tests too.
Cervical cancer is the fourth most common cancer in women around the world, killing more than 300,000 each year.
Almost nine-in-10 deaths are in low and middle income countries where there is little access to cervical cancer screening. The hope is vaccination will have an even bigger impact in those countries than wealthier nations such as the UK.