Long awaited study results have confirmed that the quadrivalent human papillomavirus (HPV) vaccine substantially reduces invasive cervical cancer risk.
Published in the New England Journal of Medicine, the study followed over 1.5 million girls and women in Sweden up to 11 years and found that the risk of cervical cancer by age 30 was 63% lower in vaccinated women compared with unvaccinated women.
Previous studies have confirmed that HPV vaccination, is effective in preventing HPV infection, genital warts, and high-grade precancerous cell changes in the cervix.
But as the vaccine was only introduced in the 2000s, until now it hadn’t been possible definitely say the vaccine reduces cases of cervical cancer itself, which is the ultimate goal of the HPV vaccination program.
Professor Jack Cuzick, a Cancer Research UK-funded cancer prevention expert at Queen Mary University of London, commented, “this is an extremely important paper and for the first time documents the impact of the HPV vaccination on the risk of cervical cancer, and not just against HPV infections and precancerous lesions.”
A vaccine to prevent cancer
HPV is a virus that infects the skin and cells lining the inside of the body. It’s an extremely common infection and in most people it doesn’t cause any problems at all. But virtually all cases of cervical cancer are caused by HPV. There are hundreds of different types of HPV, but only around 13 strains are known to be linked to cancer.
Different forms of HPV vaccine
There are various forms of the HPV vaccine that protect against different HPV strains
Quadrivalent vaccine (Gardasil): Protects again 4 types of HPV – HPV 16 and 18, which together cause around 7 in 10 cervical cancer cases in the UK, and HPV 6 and 11, which cause most genital warts. This is the vaccine available in the UK to all children aged 11 to 13 and was the vaccine used in this study.
Bivalent vaccine (Cervarix): Protects against HPV 16 and 18, has the equivalent cancer-prevent properties as the quadrivalent vaccine.
Nonvalent vaccine: (Gardasil 9): Protects against 9 types of HPV, including types 31, 33, 45, 52 and 58, as well as the HPV types mentioned above.