- Category: Women & HIV
- Published on Tuesday, 06 May 2014 00:00
- Written by Liz Highleyman
HIV positive women respond well to the Gardasil human papillomavirus (HPV) vaccine, offering them protection against cervical cancer, according to a study published in the April 14 electronic edition of Clinical Infectious Diseases. Related recent research found that both Gardasil and Cervarix are effective in people with HIV.
High-risk strains of HPV -- most commonly HPV-16 and HPV-18 -- can cause cervical, anal, and other types of cancer. A majority of people are infected with HPV soon after they become sexually active, and the Centers for Disease Control and Prevention (CDC) recommends HPV vaccination for girls age 11-26 and boys age 11-21. Studies have shown that people with HIV, especially those with compromised immune function, are more likely to be infected with multiple HPV types and less likely to clear the virus.
Erna Milunka Kojic, Susan Cu-Uvin and colleagues from Brown University conducted a study of women with HIV in the U.S., Brazil, and South Africa to determine the safety and immunogenicity -- or ability to stimulate an immune response -- of the Gardasil quadrivalent HPV vaccine designed to protect against HPV types 6, 11, 16, and 18 (types 6 and 11 cause genital warts).
AIDS Clinical Trials Group trial A5240 included 319 HIV positive women age 13-45 stratified by CD4 T-cell count: >350 cells/mm3, 200-350 cells/mm3, or <200 cells/mm3. A majority (56%) were black, 31% were Hispanic/Latina, 11% were white, and the median age was 36 years. The median CD4 count was 310 cells/mm3-- indicating a need for antiretroviral therapy (ART) -- but only 40% had undetectable HIV viral load.
- At baseline, 4% of participants were infected with all 4 HPV types covered by the vaccine.
- At 28 weeks after immunization, rates of seroconversion -- or development of protective antibodies against HPV types 6, 11, 16, and 18 -- among women not already infected with each type were:
o >350 cells/mm3: 96%, 98%, 99%, and 91%, respectively;
o 200-350 cells/mm3: 100% 98%, 98%, and 85%, respectively;
o <200 cells/mm3: 84%, 92%, 93%, and 75%, respectively.
- At all CD4 cell levels, response was better for HPV types 6, 11, and 16 compared with type 18.
- In addition to lower CD4 count, high viral load (>10,000 copies/mL) was also associated with poorer vaccine response.
- The vaccine was generally well-tolerated and no safety issues were identified.
"Quadrivalent HPV vaccine targeted at types 6, 11, 16, and 18 was safe and immunogenic in HIV-infected women 13-45 years old," the study authors concluded. "Women with HIV viral load >10,000 copies/mL and/or CD4 counts <200 cells/mm3 had lower seroconversion."
The fact that only 4% of HIV positive women in this study had all 4 HPV types covered by the vaccine indicate that the remainder stand to benefit from even though many were above the age cut-off of 26 years in the CDC guidelines. These data support the World Health Organization recommendation that women with HIV should be vaccinated against HPV.
Gardasil vs Cervarix
In a related study described in the April 15 Journal of Infectious Diseases, Lars Toft from Aarhus University Hospital in Denmark and colleagues compared the immunogenicity of Gardasil and Cervarix in people with HIV. While Gardasil protects against 4 HPV types, Cervarix is a bivalent vaccine only designed to prevent cancer-causing types 16 and 18.
This double-blind trial included 92 HIV positive women and men who were randomly assigned to received 3 doses of either Gardasil or Cervarix, at study entry and at 1.5 and 6 months later. Immunogenicity was evaluated for up to 12 months.
The researchers observed no differences in levels of antibodies against HPV-16 in participants who received Gardasil or Cervarix. However, HPV-18 antibody titers were higher in the Cervarix group than in the Gardasil group. Among people receiving Cervarix, women attained higher HPV-16 and HPV-18 antibody titers than men; no sex differences were seen among Gardasil recipients. Mild injection site reactions were more common in the Cervarix group (91% vs 70%), but no serious adverse events occurred in either arm.
"Both vaccines were immunogenic and well tolerated," the authors concluded. "Compared with Gardasil, Cervarix induced superior vaccine responses among HIV-infected women, whereas in HIV-infected men the difference in immunogenicity was less pronounced."
EM Kojic, M Kang, MS Cespedes, S Cu-Uvin, et al. Immunogenicity and Safety of a Quadrivalent Human Papillomavirus Vaccine in HIV-1-Infected Women. Clinical Infectious Diseases. April 14, 2014 (Epub).
L Toft, M Storgaard, M Müller, et al. Comparion of the immunogenicity and reactogenicity of Cervarix and Gardasil human papillomavirus vaccines in HIV-infected adults: a randomized, double-blind clinical trial. Journal of Infectious Diseases 209(8):1165-1173. April 15, 2014.
Brown University. HIV+ Women Respond Well to HPV Vaccine.Press release. April 16, 2014.