Cervical cancer is one of the most common cancers affecting women across the world, and every year, thousands of women learn that their cancer is caused by human papillomavirus (HPV). But a new study in the U.K. found that HPV vaccines have significantly reduced the risks of women developing the cancer and precancerous changes.

The study, conducted by Cancer Research UK and published in the journal The Lancet, followed an HPV vaccination program in England that started in 2008. The program offered a routine vaccination called Cervarix to teenagers, and confirmed that it was most effective in preventing cancer and precancerous issues when given to young pre-teens and teenagers before they are sexually active. It can take 15 to 20 years for cervical cancer to develop in women who have normal immune systems, according to the World Health Organization (WHO).

The vaccine reduced cervical cancer rates by 34% for those who received it at ages 16 to 18; 62% for ages 14 to 16; and 87% for ages 12 to 13. 

It also was found to reduce the risk for precancerous changes, namely grade 3 cervical intraepithelial neoplasia, by 39% for those between age 16 and 18; 75% for those between 14 and 16; and 97% for those between 12 and 13. Cervical intraepithelial neoplasia, according to the Cleveland Clinic, is a precancerous condition in which abnormal cells grow on the cervix, and is usually caused by HPV. The third grade of the condition, the one which was studied, is the most severe form of the condition. 

Michelle Mitchell, Cancer Research UK’s chief executive, said in a statement that the research is a “historic moment” that will help thousands of women. 

“We’ve been eagerly awaiting these results since the introduction of the vaccination programme,” Mitchell said. “Around 850 women die from cervical cancer each year in the UK, so we have the chance to save many lives.” 

HPV-16 and HPV-18, the most common of the more than 100 strains of HPV, are the most likely to cause cervical issues. HPV has also played a role in other cancers, such as vaginal, vulval, anal, penile, and in some cases, head and neck. 

Over an 11-year period, researchers estimate that the vaccine prevented roughly 448 cases of cervical cancers and 17,235 cases of the cervical neoplasia in England. 

Cervical cancer is the fourth most common cancer among women across the world, according to WHO, representing 7.5% of all cancer deaths among women.

In the U.S., nearly 200,000 women are diagnosed with cervical precancer every year, according to the Centers for Disease Control and Prevention, and 11,000 women are diagnosed with cervical cancer caused by HPV. More than 4,000 U.S. women die from the cancer every year.

Peter Sasiene, the study’s lead author, said in a statement that “it’s been incredible to see the impact” of the vaccine, and believes that over time, cervical cancer may become far less common with the help of vaccination.

“Assuming most people continue to get the HPV vaccine and go for screening, cervical cancer will become a rare disease,” he said. “This year we have already seen the power of vaccines in controlling the COVID-19 pandemic. These data show that vaccination works in preventing some cancers.” 

Li Cohen

Li Cohen is a social media producer and trending reporter for CBS News, focusing on social justice issues.