A vaccine for human papillomavirus (HPV) may benefit women with HIV, even if they have already been exposed to HPV, according to a study released by an NIH research network.
The study, published in the Journal of Acquired Immune Deficiency Syndromes in an article titled "Prevalence and Risk Factors for HPV in HIV-Positive Young Women Receiving Their First HPV Vaccination", notes that more than 45% of women with HIV appear never to have been exposed to the most common high-risk forms of HPV. That contradicts earlier studies, which found that many women with HIV were more likely than were women without the AIDS virus to have conditions associated with HPV, such as precancerous conditions of the cervix, as well as cervical cancer.
"Our results show that for a significant number of young women, HPV vaccine can still offer benefits. This is especially important in light of their HIV status, which can make them even more vulnerable to HPV's effects," says the study’s first author, Jessica Kahn, M.D., of Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine.
"Even among women who test positive for one type of HPV, the vaccine may effectively prevent infection with others—especially high-risk forms that cause cancer," Dr. Kahn said.
In the study, researchers analyzed blood and tissue samples from 99 HIV-positive women between the ages of 16 and 23 who were given an initial HPV vaccination. The researchers then examined the samples for evidence of an existing HPV infection as well as previous exposure to the virus.
Researchers tested for the presence of 41 of more than 100 existing types of HPV virus, including 13 high-risk types. They found that 75% of the women had an existing HPV infection with at least one type, with 54% testing positive for a high-risk type. When examining the two types that cause 70% of cervical cancers (HPV-16 and HPV-18), however, the researchers found that nearly half of the women had no existing infection with either type and showed no evidence of exposure to them.
When the women in the study received their first HPV vaccination, 12% had an existing HPV-16 infection while 5% had an HPV-18 infection. Because of their HIV status, these women may be more likely to develop cervical cancer or to develop a cancer that is hard to treat, the researchers say.
Also, when they tested for each type of HPV individually, they found that nearly 75% of the women had no current HPV-18 infection and no evidence of previous exposure. For HPV-16, more than half (56%) did not have a current infection or previous exposure.