In a new study, researchers found that women vaccinated against HPV have a significantly lower risk of developing cervical cancer, and the positive effect is most pronounced for women vaccinated at a young age.
This is the first time that scientists, on a population level, are able to show that HPV vaccination is protective not only against cellular changes that can be precursors to cervical cancer but also against actual invasive cervical cancer.
The research was conducted by a team at Karolinska Institutet in Sweden.
HPV (human papillomavirus) is a group of viruses that commonly causes genital warts and different types of cancer, including cervical cancer, a disease that globally kills more than 250,000 women a year.
More than 100 countries have implemented national vaccination programs against HPV, and Sweden as of August 2020 also includes boys in this program.
Previous studies have shown that the HPV vaccine protects against HPV infection, genital warts and precancerous cervical lesions that could develop into cancer of the cervix.
However, there is a lack of large population-based studies that on an individual level have studied the link between the HPV vaccine and so-called invasive cervical cancer, which is the most severe form of the disease.
In this study, the researchers during a period of 11 years followed almost 1.7 million women between the ages of 10 and 30. Of those women, more than 500,000 were vaccinated against HPV, the majority before the age of 17.
Nineteen vaccinated women were diagnosed with cervical cancer compared to 538 unvaccinated women.
The researchers’ analysis shows that HPV vaccination was linked to a much-reduced risk of cervical cancer and that girls vaccinated before age 17 reduced their risk of cervical cancer by 88%.
Women vaccinated between ages 17 and 30 halved their risk of cervical cancer compared to unvaccinated women.
The team says girls vaccinated at a young age seem to be more protected, probably because they are less likely to have been exposed to HPV infection and given that HPV vaccination has no therapeutic effect against a pre-existing infection.
One author of the study is Jiayao Lei, a researcher at the Department of Medical Epidemiology and Biostatistics.
The study is published in the New England Journal of Medicine.
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