About 100 countries have introduced vaccines against human papillomavirus (HPV) to try to eliminate cervical cancer.

An observational study from England offers the best evidence yet that they do just that.

Earlier randomized controlled trials and surveillance studies have shown HPV vaccinations can prevent HPV and the precancerous condition cervical intraepithelial neoplasia (CIN), but direct evidence of its value in protecting against cervical cancer has been somewhat lacking.

Enough time has now passed since England began administering Cervarix, a vaccine against the two most common HPV types, to evaluate its effectiveness in preventing cervical cancer.

The study, published in the journal the Lancet, finds cervical cancer rates fell 34-87%, and that females who received Cervarix at ages 12-13 received the most protection. The lowest risk reauction occurred among females vaccinated at 16-18 years old. Those vaccinated at ages 14–16 fell in the middle and saw a 62% reduction in cervical cancer risk.

That's as expected, as vaccines work best when given prior to exposure.

Risk reduction for CIN was higher but followed the same pattern, reducing risk 39%, 75% and 97%, from the oldest cohort to the youngest.

England began routinely offering Cervarix to females aged 12–13 years in September 2008. A catch-up program was also established for females aged 14–18 years old from 2008–10.

England has since switched to Gardasil, a vaccine that protects against four HPV types.

More research is needed, but the limited study supports the idea that eligible females should get the HPV vaccine, ideally at the earliest age it is offered, to protect themselves and future generations.