(RxWiki News) One precursor to cervical cancer are lesions that develop on the cervix from a virus called HPV. But the worst strains of HPV can be prevented with a vaccine.
Human papillomavirus, or HPV, is a sexually transmitted disease. However, it can also be transmitted by skin-to-skin contact, even to non-sexually-active children.
Two vaccines exist to prevent HPV: Cervarix protects against two strains that can cause cervical cancer, and Gardasil protects against those strains and two others that cause genital warts.
A recent study found that three doses of the HPV vaccine effectively reduced women's risk of having the cervical lesions associated with developing cervical cancer.
Those who received three doses had about double the protection of those who received only two doses of the vaccine.
"Discuss the HPV vaccine with your OB/GYN."
This study, led by Elizabeth Crowe, of the University of Queensland School of Population Health in Australia, looked at how effective the HPV vaccine is for preventing cervical lesions. Australia had instituted a nationally funded vaccination program with the HPV virus.
This study looked at women who were aged 12 to 26 in 2007 (and therefore eligible for the free vaccine) and who received their first Pap smear test between April 2007 and March 2011.
Pap smear tests are used to detect abnormalities on a woman's cervix that could indicate pre-cancerous lesions caused by HPV.
The researchers compared the vaccination status of three groups of women: 1,062 women who had confirmed high-grade cervical abnormalities; 10,887 women who had any other kind of abnormality; and 96,404 women who had normal lab results.
The researchers found that women who had received three doses of the HPV vaccine were 46 percent less likely to have high-grade cervical abnormalities and 34 percent less likely to have other abnormalities compared to those who didn't get the vaccine.
Therefore, the vaccine was regarded as 46 percent effective in preventing cervical abnormalities and 34 percent effective in preventing other abnormalities that may have been caused by HPV.
Put another way, for every 125 women who received three doses of the vaccine, one would avoid having high-grade cervical abnormalities. For every 22 women who received three doses of the vaccine, one would avoid having other cervical abnormalities.
The vaccine was 21 percent effective at preventing any cervical abnormalities (high-grade or otherwise) when women received two doses.
The researchers therefore concluded that the HPV vaccine did provide significant protection against cervical lesions and similar abnormalities in the women who received it.
This study was published March 4 in BMJ. The research did not receive external funding explicitly for this study.
The authors were supported by the following: University of Queensland, NHS Borders, the Australian Research Council, the National Health and Medical Research Council, Victorian Cytology Service and the Children's Health Foundation Queensland.
In the past, two authors received financial support from Merck and BioCSL, and one of them also received support from GlaxoSmithKline.
The University of Queensland receives royalties from sales of Gardasil, the HPV vaccine manufactured by Merck. GSK also manufactures the HPV vaccine Cervarix.
