Background
Women living with HIV are more likely to be infected with the human papillomavirus (the virus that causes cervical cancer). Not only is HPV infection double in women living with HIV compared to women without HIV, but rates of invasive cervical cancer are 4 times greater in women living with HIV.
HPV vaccines have shown a high degree of safety, good immune responses, and very good protection from infection and pre-cancer in populations of women without HIV. Although the vaccines appear to be safe and generally create a good immune response in women living with HIV, no other studies to-date have published findings on how the vaccine works against cervical pre-cancers.
Summary of evidence
The HPV in HIV Study (also known as CTN 236) enrolled 420 women living with HIV from across Canada and gave the Gardasil quadrivalent HPV vaccine (which protects against four types of HPV) in a three-dose schedule. Participants were aged 9 and greater, with the eldest participant being age 66 at the time of first vaccination. Findings from the study were recently published in the journal Clinical Infectious Diseases.[1]
The study found that women living with HIV experienced rates of persistent HPV infection, genital warts, and pre-cancer of the cervix caused by higher risk HPV types that were similar to the rates observed in an HIV-negative group from another study.[2] Rates of persistent HPV infection were, however, lower than the rates seen in unvaccinated women living with HIV (so the vaccine did show some protection). Of the breakthrough HPV infections, HPV18 was the most frequently seen type.
Clinical implications
Pap screening in women living with HIV remains important.
Despite the rates of HPV vaccine failure being higher in women living with HIV than women without HIV, overall rates of HPV vaccine failure in women living with HIV were low. Although protection from the vaccine is not as complete as that seen in women without HIV, an important benefit from vaccination appears to be present.
It is also important to realize that women living with HIV have other HPV infections that are not included in the HPV vaccine, which means regular screening for cervical cancer should still be offered for these women.
References
- McClymont E, Lee M, Raboud J, et al; for the CTN 236 HPV in HIV Study Team. The efficacy of the quadrivalent human papillomavirus vaccine in girls and women living with HIV [published online July 7, 2018]. Clin Infect Dis. doi.org/10.1093/cid/ciy575
- Muñoz N, Manalastas R Jr, Pitisuttithum P, et al. Safety, immunogenicity, and efficacy of quadrivalent human papillomavirus (types 6, 11, 16, 18) recombinant vaccine in women aged 24-45 years: a randomised, double-blind trial. Lancet 2009; 373:1949–57