The safety and potential efficacy of vaccination against the human papillomavirus (HPV) in HIV-positive women has been indicated in the results of a recent clinical trial. The outcome of this study has clearly shown that a vaccine protective against four common strains of HPV (GARDASIL) is well-tolerated and shows a solid immune response in HIV-positive women, even those above the typical age range for vaccination.
The leading cause of invasive cervical cancer worldwide is HPV infection and incidence rates are over four times higher in HIV-positive compared to HIV-negative women. This results in higher rates of recurrent infection and progression to cervical cancer, particularly in countries where HIV is more prevalent and cervical cancer screening is limited or non-existent.
“HPV infection and associated cancers disproportionately affect women with HIV,” said Dr. Deborah Money, the lead investigator for the HPV in HIV Study Group “the HPV vaccine provides a tangible opportunity for primary cancer prevention of significant scale.”
The effectiveness of several HPV vaccines has been shown in HIV-negative women but there is limited evidence of their success in women living with HIV. This study, which enrolled 372 participants, was one of the first in the world to examine this question and demonstrated that HIV-positive women had strong immune responses to the vaccine, creating antibodies to protect against future infection at comparable rates to the HIV-negative population.
Women with a lower HIV viral load – amount of detectable HIV in the blood – had a better immune response to HPV vaccination than those without HIV viral suppression. By including women up to the age of 66, the study was able to show that the HPV vaccine has significant potential to benefit older HIV-positive women in addition to HIV-positive girls and young women.
The study authors concluded that HPV vaccination in HIV-positive women can result in a good immune response which promises to prevent HPV infection and cervical cancer. Of importance, the study showed that HIV positive women respond best to this vaccine when their HIV virus is fully suppressed. Secondly, the research team called for an extension of coverage to women above the vaccination age limits, particularly in low- and middle-income countries where cervical cancer screening is limited.
“Appropriate vaccination of women living with HIV is an important step in global eradication of cervical cancer and can be lifesaving,” said Dr. Money.
This study was funded by the Canadian Institutes for Health Research (CIHR) and supported by the CIHR Canadian HIV Trials Network (CTN). The complete publication is available online in the journal Vaccine. Details are also available by visiting the CTN website at ctnplus.ca or by contacting ctninfo@ctnplus.ca.
