Young women living with HIV may benefit from vaccinations that protect against cervical cancer, according to a new study showing that many HIV-positive women averaging 21 years of age are negative for the human papillomavirus (HPV) types typically associated with tumors, according to a new analysis. These encouraging findings were presented at the 2nd International Workshop on HIV and Women, held January 9 and 10 in Bethesda, Maryland, and were reported by the National AIDS Treatment Activist Project (NATAP).

Two HPV vaccines are approved for use in the United States: Gardasil and Cervarix. The U.S. Centers for Disease Control and Prevention (CDC) recommends them for all 11- and 12-year-old girls and all females between 13 and 26 years of age who have not been vaccinated or completed the three-injection series. The vaccines help protect against four HPV genotypes, two of which—types 16 and 18—are major causes of cervical cancer.

The effectiveness of HPV vaccination in women living with HIV isn’t known, with some experts suggesting that efficacy will be lower, on the assumption that many young women infected with HIV have also been infected with HPV genotypes 16 and/or 18. A clinical trial, conducted by the Adolescent Medicine Trials Network for HIV/AIDS Interventions, is being conducted to answer these questions.

Early results from the study, presented by Jessica Kahn, MD, of the University of Cincinnati and her colleagues, help answer one of these questions. According to her team’s results, most of 99 women enrolled to receive HPV vaccination were negative for high-risk HPV types.

The 99 women were on average 21.4 years old, and 80 percent were black. Thirty percent of the enrolled adolescents and young women had zero to five lifetime male sex partners, 32 percent had six to 10, and 38 percent had more than 10. According to the NATAP report, more than one quarter of these young women had vaginal sex more than 10 times in the 90 days before enrolling in the study, and 36 percent had vaginal sex two to 10 times in the past 90 days.

Three quarters of women tested positive for any HPV type, while only 15 percent were positive for types 16 and/or 18. Specifically, of the four genotypes covered in the Gardasil vaccine being used in the study, positivity rates were generally low: 2 percent for type 6, 1 percent for type 11—both of which can cause noncancerous warts and dysplasia—12 percent for type 16 and 5 percent for type 18.

Three factors were found to be associated with a higher risk of being infected with high-risk HPV types before entering the study: being black, having an HIV viral load above 400 copies andengaging in vaginal sex at least once in the 90 days before entering the clinical trial.

In conclusion, the researchers suggested that the relatively high prevalence of any HPV or HPV 16 or 18 compared with the general population supports current advice to target 11- and 12-year-old girls for vaccination, before they are likely to begin sexual intercourse. But, NATAP writes, “because the ‘vast majority’ of these young HIV-positive women remained negative for these HPV types before vaccination, the investigators argued [that] young HIV-positive women should be vaccinated.”