HPV Vaccine: Harbinger of Immunizations to Come

HPV Vaccine: Harbinger of Immunizations to Come

In a randomized, controlled trial, a new vaccine against human papillomavirus type 16 was 100% effective.

Human papillomavirus type 16 (HPV-16) infection is associated with cervical cancer. Any successful immunization program for this condition will have to vaccinate young women before they become sexually active. In a multisite, double-blind, industry-sponsored, randomized clinical trial, 1533 evaluable women (age range, 16 to 23) received placebo or HPV-16 virus-like-particle vaccine at the time of enrollment and again 2 and 6 months later. In this interim analysis, women were followed for a median of 17.4 months after the last immunization.

The efficacy of the vaccine was 100%. No cases of HPV-16 infection occurred in the 765 women in the vaccine group, but 41 cases occurred in the 768 women in the placebo group. The incidence of persistent HPV-16 infection was 3.8 per 100 woman-years in the placebo group and 0 per 100 woman-years in the vaccine group. The results were essentially unchanged when the analysis included an additional 60 women with general protocol violations.

Comment: This vaccine appears to be highly effective, but cervical cancer is also caused by other HPV types not represented in this experimental vaccine. It is unlikely that any HPV vaccine will soon be commercially available. An editorialist notes that that this vaccine protects against the preinvasive disease associated with HPV-16 and also against persistent and transient infection. Because it is important to vaccinate women before they become sexually active, physicians who care for adolescents are critical to any national immunization program. This vaccine is the first of what will probably be many to prevent sexually transmitted diseases.

— Howard Bauchner, MD

Published in Journal Watch Pediatrics and Adolescent Medicine December 6, 2002