HPV Vaccine Offers Protection from Anal Infection

A new study finds that vaccination against human papillomavirus (HPV) can protect women against anal HPV infections that can lead to cancer. The study, published online yesterday in The Lancet Oncology, looked at the performance of Cervarix, made by GlaxoSmithKline, a vaccine that guards against HPV 16 and 18, the strains that cause most cases of anal cancer.

Participants in the study were Costa Rican women 18-25 in good health who were not pregnant or breastfeeding. They received either the HPV vaccine or a control hepatitis A vaccine in three doses—at enrollment, one month later, and six months later.

Four years after the initial dose, 4,210 women provided anal specimens that were used to determine how effective the vaccine had been at preventing HPV 16/18 infection. For all those who received the HPV vaccine, efficacy against anal HPV 16/18 infection was 83.6%, compared with 76.4% in the cervix. Among those who were negative for HPV DNA and antibodies when they were first vaccinated, the vaccine efficacy against HPV 16/18 infection in the anus was 83.6% compared with 87.9% in the cervix

Researchers concluded that the vaccine offers strong protection against anal HPV infection, particularly among those who are HPV negative when they first receive the vaccine.

Source:

Efficacy of a bivalent HPV 16/18 vaccine against anal HPV 16/18 infection among young women: a nested analysis within the Costa Rica Vaccine Trial (abstract) [The Lancet Oncology]