HIV+ women respond well to HPV vaccine

A three-nation clinical trial found that a vaccine can safely help the vast majority of HIV-positive women produce antibodies against the cancer-causing human papillomavirus, even if their immune system is weak and even if they’ve had some prior HPV exposure.

HIV-positive women respond well to a vaccine against the human papillomavirus (HPV), even when their immune system is struggling, according to newly published results of an international clinical trial. The study’s findings counter doubts about whether the vaccine would be helpful, said the Brown University medical professor who led the study. Instead, the data support the World Health Organization’s recommendation to vaccinate women with HIV.

HPV causes cervical and other cancers. The commonly used HPV vaccine Gardasil had not been tested in seriously immune-suppressed women with HIV, said Dr. Erna Milunka Kojic, associate professor of medicine at the Warren Alpert Medical School of Brown University and The Miriam Hospital. Despite the WHO recommendation, she said, skeptics have wondered whether the vaccine would be safe and helpful for women with weakened immune systems who were already likely to have been exposed to HPV through sex. Vaccines are often less effective in HIV-positive people.

To address that debate, Kojic’s study, dubbed “AIDS Clinical Trials Group Protocol 5240,” measured the safety and immune system response of the vaccine in HIV-positive women aged 13 to 45 with a wide range of immune statuses.

In the vast majority of the 315 volunteers who were vaccinated at sites in the United States, Brazil, and South Africa, the vaccine built up antibodies against HPV and posed no unusual safety issues during the 28 weeks they were each involved.

“The vaccine works for HIV-infected women in terms of developing antibodies,” Kojic said.

Co-author Dr. Susan Cu-Uvin, professor of public health and of obstetrics and gynecology at Brown, said women with HIV are especially susceptible to cervical cancer from HPV because their weakened immune systems are less able to clear the virus. That makes vaccinating HIV-positive women especially important, so long as it’s safe and they respond.

Response across the board

To investigate that response in the context of HIV, the study grouped women by their CD4 cell count, a measure of immune system health. Group A had CD4 counts above 350, group B rested between 200 and 350. Group C was composed of women with counts below 200, the defining level of AIDS for which response to an HPV vaccine had not yet been studied.

Gardasil is a “quadrivalent” vaccine, in that it protects against four types of HPV (6, 11, 16, and 18). Each group in the study, therefore, had four measures of “seroconversion,” or the buildup of a significant army of antibodies against each type of HPV. The researchers determined that seroconversion in at least 70 percent of patients for each HPV type would define success.