A vaccine for cervical cancer
Nathan Seppa
From Washington, D.C., at the Interscience Conference on Antimicrobial Agents and Chemotherapy
In a preliminary study, a vaccine against a virus that can cause cancer has proved 94 percent effective in women. The success sets the stage for an enhanced version of the vaccine and the massive trial needed for government approval of the final product, which is intended to protect against the human papillomavirus (HPV).
Some HPV strains cause cervical cancer, while others are responsible for genital warts (SN: 11/23/02, p. 323: http://www.sciencenews.org/articles/20021123/fob1.asp; 3/3/01, p. 132: Available to subscribers at http://www.sciencenews.org/articles/20010303/fob2.asp). In the new trial, researchers gave 768 young women three injections of the vaccine, and 765 similar women three placebo shots. Over the following 3.5 years, only 7 women who were vaccinated developed an HPV infection, compared with 111 of those getting the inert shots, says Constance Mao of the University of Washington School of Medicine in Seattle.
An HPV infection can lead to aberrant cervical-cell growth, the kind detectable on a Pap smear. If not removed, the cells can progress to precancerous lesions and sometimes cancer. In this trial, none of the vaccinated women developed such aberrant cell growth, whereas 24 of those receiving the placebo did, Mao said.
Merck Research Laboratories of West Point, Pa., has created the enhanced vaccine using proteins from four HPV strains—two that cause cancer and two that cause genital warts. Researchers have enrolled 25,000 men and women worldwide for this vaccine's large-scale test.
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References:
Mao, C., et al. Prophylactic human papillomavirus (HPV) 16 virus-like particle vaccine prevents HPV 16-related cervical intraepithelial neoplasia (CIN) 2-3. 44th Interscience Conference on Antimicrobial Agents and Chemotherapy. Oct. 30–Nov. 2. Washington, D.C. Abstract.
Further Readings:
Harro, C.D. … J.T. Schiller, et al. 2001. Safety and immunogenicity trial in adult volunteers of a human papillomavirus 16 L1 virus-like particle vaccine. Journal of the National Cancer Institute 93(Feb. 21):284–292. Available at http://jncicancerspectrum.oxfordjournals.org/cgi/content/full/jnci;93/4/284.
Seppa, N. 2002. Virus stopper: Vaccine could prevent most cervical cancers. Science News 162(Nov. 23):323. Available at http://www.sciencenews.org/articles/20021123/fob1.asp.
______. 2001. Vaccine may prevent some cervical cancers. Science News 159(March 3):132. Available to subscribers at http://www.sciencenews.org/articles/20010303/fob2.asp.
zur Hausen, H. 2001. Cervical carcinoma and human papillomavirus: On the road to preventing a major human cancer. Journal of the National Cancer Institute 93(Feb. 21):252–253. Available at http://jncicancerspectrum.oxfordjournals.org/cgi/content/full/jnci;93/4/252.
Sources:
Constance Mao
University of Washington
Harborview Women's Clinic
Harborview Medical Center
Box 359854
Seattle, WA 98104-2499
From Science News, Volume 166, No. 21, November 20, 2004, p. 332.
