An exciting new study in Scotland found no cases of invasive cervical cancer in young women who had gotten the HPV vaccine by the time they were 14. The study also found that women vaccinated between ages 14 and 22 had lower rates of cervical cancer than unvaccinated women.

Scotland began a vaccination program in 2008. It offered the HPV vaccine to girls in their first year of secondary school (ages 12 or 13). To determine how effective the vaccine was, researchers analyzed health records for all young women born between 1988 and 1996.

The results show that the vaccination was 100% effective against cervical cancer when given at ages 12 or 13, 86% effective when given between ages 14 and 16, and 39% effective when given at ages 17 or 18. The study found no protective benefits when the vaccine was given over the age of 18.

It is important to note that many women who were vaccinated as part of this program are in their 20s and 30s now, which is still quite young. The average age for diagnosis of cervical cancer in the United States, for example, is 50. To truly understand the protection provided by the vaccine, researchers will need to continue following young people who’ve gotten the shot into their 60s and 70s.

In addition, the women in this study received a bivalent version of the HPV vaccine. It protected against HPV types 16 and 18 which are known to cause most cervical cancers, as well as other types known to cause genital warts. Today, both the U.K. and the U.S. use a nonavalent vaccine. It protects against nine types of HPV known to cause cervical and other cancers such as anal, vulvar/vaginal, and oropharyngeal cancers (those of the head and neck). Again, to truly understand the protection provided by the vaccine, we will need to follow people given this newer version of the vaccine for several decades as well.

Still, this study offers more proof that vaccinating young people early provides the best protection against cervical cancer. It also confirmed that younger people (12 and 13) need fewer shots (one or two) to be fully protected while people starting later should get three shots.

The HPV vaccine is recommended for people of all sexes and genders between ages 9 and 26 though it can be given up to age 45. The CDC recommends that the HPV vaccine be part of the routine vaccinations given to young people at ages 11 or 12.

Experts in the U.S. have said that we can eliminate cervical cancer in this country with widespread HPV vaccination.