HPV-16 Vaccine Effective in Preventing Persistent Infection and Cin


Figure  .

New HPV-16 vaccine may be effective in preventing cervical cancer.

The editorial title, “The Beginning of the End for Cervical Cancer?” which appeared in the November 21 issue of The New England Journal of Medicine (2002;347:1645–1651) was certain to attract attention.

In the editorial, Christopher Crum, MD, Director of the Women's and Perinatal Pathology Division at Brigham and Women's Hospital in Boston, and Professor of Pathology at Harvard Medical School, commented on another article in the same NEJM issue—“A Controlled Trial of a Human Papillomavirus Type 16 Vaccine.” In the article, authors reported on a study trial led by Laura A. Koutsky, PhD, Professor of Epidemiology from the University of Washington, and members of the Proof of Principle Study Investigative Group from several other institutions.

The results of this trial showed that no cases of persistent HPV-16 infection or HPV-16-related cervical intraepithelial neoplasia (CIN) were observed among the 768 women who received the vaccine during a median follow-up period of about 17 months. Among the 765 women who received a placebo vaccine, 41 developed persistent HPV-16 infection, and nine developed HPV-16-related CIN. Overall, the vaccine was well tolerated and not associated with any serious adverse events.

In his editorial, Dr. Crum noted that an effective vaccine against five high-risk HPV types would prevent about 85 percent of cervical cancer cases, and that adding the two most common low-risk HPV types would eliminate most cases of genital warts and most abnormal cervical cytology results.

“Proof that vaccines may be able to prevent much cervical cancer in the future is a very exciting development,” said Debbie Saslow, PhD, Director of Breast and Gynecologic Cancer for the American Cancer Society.

“But with follow-up short at this point, the long-term efficacy and side effects of the vaccine studied can't be known yet,” Saslow said. “Cervical cancer vaccines are not likely to be widely available for several years, and this vaccine is not designed to eliminate the virus among those already exposed to HPV or as a therapeutic vaccine for women diagnosed with CIN or invasive cervical cancer.

“Since HPV-16 is present in and believed to be the main etiologic agent for approximately half of all high-grade CIN lesions and cervical cancers, widespread use of a vaccine with this degree of efficacy would very substantially reduce cervical cancer incidence and mortality as well as the costs associated with screening, prevention, and treatment of this disease,” Saslow said. “But any woman who has ever been sexually active may be at risk for having a lasting HPV infection. Vaccines are not likely to eliminate the need for cervical cancer screening for many years to come, and will likely have the biggest initial impact in lower-income nations where screening is available to women only once or twice in their lifetimes, if at all.”