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Vaccine Shown to be Highly Effective in Preventing Cervical Cancer

The results from a two year study indicate that a new vaccine designed to prevent the two strains of human papillomavirus (HPV), HPV 16 and 18 that are highly correlated with the development of cervical cancer and pre-cancerous cervical lesions, is highly effective. The pharmaceutical company Merck, Sharp & Dohme tested its vaccine, Gardasil, in more than 12,000 women in the U.S. and 12 other countries.1

The women who participated in the trials were between the ages of 16 and 26, reported that they were sexually active, and had not previously been infected with HPV 16 or 18. Half of the women received three doses of the vaccine over six months while the other half received placebo injections. Among the women who received the active vaccine, none developed HPV 16 or 18. Among the control group, 21 cases of HPV 16 or 18 were detected. Merck was excited by such positive results and a spokesperson commented that, “to have 100 percent efficacy is something that you have very rarely.”2

There are over 100 strains of HPV, but only approximately 30 affect the genitals. Of these, some can lead to genital warts and others to cervical cancer. HPV 16 and 18 specifically are responsible for 70% cervical cancer.3 HPV is extremely prevalent in the U.S. and often goes undetected as most people’s immune systems fight off the virus before they are aware of the infection.

Gardasil will preempt any cancerous growths in women whose immune systems do not fight off the initial HPV 16 or 18 infection. The drug is also designed to prevent infection with HPV strains 6 and 11, which cause 90% of genital warts.4

Merck plans to have Gardasil on the market by 2006 after applying for Food and Drug Administration approval later this year. The drug will first be available to women, but may later be available to men as well and could help prevent HPV-related anal cancer. Another drug company, GlaxoSmithKline is also developing a cervical cancer vaccine that has tested well, but does not prevent the HPV strains that cause genital warts.5 Both drug companies are continuing with research, and Merck will soon be able to report on the effectiveness of the vaccine over four year trials.

Effective vaccines that ultimately prevent cervical cancer will have huge public health implications nationally and globally. Each year in the U.S., over 10,000 women are diagnosed with cervical cancer and roughly 4,000 women die from it. The cervical cancer mortality rate in the U.S. is significantly lower than it is globally because of widespread use of the pap smears which can detect abnormal changes in cervical cells before they become cancer. Around the world, the number of deaths each year from cervical cancer reaches 300,000. A doctor at the American Cancer Society noted that with effective distribution, these vaccines could prevent at least 70% of cervical cancer deaths globally.6

Despite the potential for great improvements in women’s health there have been some critics of these vaccines. Many U.S. conservative groups are wary of widespread promotion of the vaccine, claiming that it may undermine abstinence-only-until-marriage messages.7 The Family Research Council, an ardent supporter of abstinence-only-until-marriage programs and anti-choice policies, has argued that “giving the HPV vaccine to young women could be potentially harmful, because they may see it as a license to engage in premarital sex.”

“Some people have raised the issue of whether this vaccine may be sending an overall message to teenagers that, ‘We expect you to be sexually active,’” said Reginald Finger, medical analyst for the conservative group Focus on the Family.9

Such groups may be preparing to negatively frame public discussion around the vaccine and to oppose policies that would make vaccination mandatory. Indeed, such opposition is in a position to affect the availability of the vaccines: a former member of Focus on the Family serves on the federal panel that is playing a pivotal role in deciding how the vaccine is used, for example.10

“This is an incredibly important breakthrough in preventative medicine,” said William Smith, vice president for public policy at the Sexuality Information and Education Council of the United States (SIECUS). He continued, “it is disturbing that even when faced with the prospect of an effective cancer vaccine the radical right is still willing to put their hyper-moralizing ahead of the health and well being of our nation’s families and communities.”


  1. Denise Grady, “Vaccine Prevents Most Cervical Cancer,” New York Times , 7 October 2005, accessed 12 October 2005, <>.
  2. “Study: Vaccine Blocks Cervical Cancer,” , 6 October 2005, accessed 12 October 2005, <>.
  3. Grady.
  4. Ibid.
  5. “Study: Vaccine Blocks Cervical Cancer.”
  6. Grady.
  7. Rob Stein, “Cervical Cancer Vaccine Gets Injected With a Social Issue: Some Fear a Shot For Teens Could Encourage Sex,” Washington Post , 31 October 2005, accessed 12 November 2005, <>.
  8. Debora MacKenzie, “Will Cancer Vaccine Get to All Women?” , 18 April 2005, accessed 13 October 2005, <>.
  9. Ibid.
  10. Ibid.