Women over the age of 40 are not likely to benefit from a vaccine designed to prevent human papillomavirus (HPV), according to the results of a study published in the Journal of the National Cancer Institute.1 HPV has been shown to cause cervical cancer.
Human papillomaviruses consist of more than 100 different viruses. Some types of HPV cause warts on the hands or feet; others cause genital warts; and some have been linked with cancer, most notably cervical cancer. The types of HPV most commonly linked with cervical cancer are HPV16 and HPV18, but several other high-risk types contribute to cancer as well.
The types of HPV that cause cervical cancer or genital warts are transmitted sexually. HPV infection is extremely common and generally occurs soon after an individual becomes sexually active. Although most infections resolve on their own, some persist and can lead to precancerous or cancerous changes to the cervix, vulva, vagina, penis, and anus. HPV infection has also been linked to certain cancers of the head and neck.
Recognition of the link between HPV and cervical cancer led to the development of vaccines designed to prevent infection with certain high-risk types of HPV.
Currently, there are two vaccines approved for the prevention of HPV 16 and 18: Gardasil® and Cervarix®. Gardasil also protects against HPV 6 and 11, which are associated with most types of genital warts. The vaccines are recommended for girls as young as age 9 and up to age 26. Little data exists, however, to determine whether older women will benefit from the vaccines.
A study of more than 9,000 Costa Rican women ages 19 to 97 evaluated the patterns of HPV infection as women age. The researchers found that the rate of newly detected infections declined with age—from 35% in women ages 18-25 to 13.5% in women over the age of 42. In both younger and older women, new infections typically cleared up without treatment within two years. They found that new infections typically did not progress to worse disease in older women.
Based on their findings, the researchers concluded that HPV vaccination was not likely to be beneficial for older women. The vaccinations are used to prevent new infections, and older women are not getting many new infections.
1 Rodriguez AC, Schiffman M, Herrero R, et al. Longitudinal study of human papillomavirus persistence and cervical intraepithelial neoplasia grade 2/3: Critical role of duration of infection. Journal of the National Cancer Institute. 2010; 102: 315-324.