The NHS launched human papillomavirus (HPV) immunization program to prevent cervical cancer in England 13 years ago. Now, thanks to a study funded by Cancer Research UK, there is solid proof that this vaccination program has stopped thousands of women from experiencing pre-cancerous changes to cells and from developing the disease altogether.

According to the study, which looks at data from the HPV immunization program that used the Cervarix vaccine, cervical cancer rates in women who were administered the vaccine between the ages of 12 and 13 were an impressive 87 percent lower than in an unvaccinated population. The cancer cases in this age group dropped from 50 per year to only five.

For women who were offered the vaccination between the ages of 14 and 16, cervical cancer rates were reduced by 62 percent, while cervical cancer rates of those who were immunized between the ages 16 and 18 dropped by 34 percent.

Currently, the program uses a different vaccine, called Gardasil, to immunize girls and boys aged 12 and 13.

Based on the data used for this study, researchers found that there was a 97 percent drop in pre-cancerous changes to cells in women who were vaccinated at 12 and 13 years of age, a 75 percent drop for those vaccinated between the ages of 14 and 16, and finally, a 39 percent drop in women vaccinated between the ages of 16 and 18.

If the vaccination program had not been rolled out, experts calculate that almost 36,000 women’s cells would have experienced pre-cancerous changes. This is the first time that researchers have been able to provide direct evidence of the prevention of cervical cancer through HPV vaccination.

Cancer Research UK is excited about the results, which were better than they had anticipated them to be. “It’s been incredible to see the impact of HPV vaccination and now we can prove it prevented hundreds of women from developing cancer in England,” says the study’s lead author Professor Peter Sasieni. “We’ve known for many years that HPV vaccination is very effective in preventing particular strains of the virus, but to see the real-life impact of the vaccine has been truly rewarding.”

Source study: The Lancet—The effects of the national HPV vaccination program in England, UK, on cervical cancer and grade 3 cervical intraepithelial neoplasia incidence: a register-based observational study