In the news ... 2006 archive

First-ever HPV Vaccine Approved

June 13, 2006

On June 8, 2006 the US Food and Drug Administration (FDA) approved the first preventive vaccine against the human papillomavirus (HPV), the virus which causes most cases of cervical and anal cancer. The vaccine is designed to prevent infection from two forms of HPV that cause around 70% of all cases of cervical cancer in the US. It also provides some protection against another two strains of HPV that cause up to 90% of cases of genital warts.

The old adage, an ounce of prevention is worth a pound of cure, is never truer than when we consider infectious diseases. This is particularly true of viruses, which are—in many ways—the most difficult disease-causing (or pathogenic) organisms to treat. Therefore the approval of this vaccine to prevent the cancer-causing sexually transmitted virus is a remarkable and important development.

HPV is a family of over 100 closely related viruses—some of which cause warts. Several strains of HPV can infect tissues in the genital region, sometimes leading to the development of warts, but most often causing no visible or noticeable symptoms. HPV is the most common sexually transmitted infection, affecting over half of all sexually active adults in the US.

However, more troubling than genital warts is the link between some strains of HPV and cancers of the cervix, vagina and anus. In fact, HPV is the leading cause of cervical cancer.

Two major companies are developing vaccines against HPV: Merck and GlaxoSmithKline (GSK). The Merck vaccine, which will be marketed as Gardasil, is further along in development. It has been tested in over 20,000 people. It is given as a series of three shots, given over six months. It is expected to cost somewhere from $300–$500 for the three-shot series. While costly, it is likely far less than the cost of treating cervical cancer and genital warts. Despite this, however, the price will likely limit the ability to conduct widespread vaccination programs.

This vaccine is for people who have not been infected with HPV. Because it is so common among sexually active adults, the vaccine is primarily intended for pre-sexual people. The FDA has recommended it for girls aged 11–12 and are considering use in girls aged 13–15 and women as old as 26. The vaccine has been studied in a small number of men and older women, but not in enough adults to prove effectiveness in that population.

While these vaccines are a welcome development, there are several important unanswered questions and concerns that will need to be addressed. The first is that this vaccine has not been studied in many men. Merck has announced plans to study the vaccine in young males. The GSK vaccine is being studied in young men.

For now, this vaccine is unlikely to be used by people already living with HIV, as most people with HIV have also already been exposed to HPV. Merck does not believe their vaccine will have any effect in people already infected by HPV so they do not plan on studying it this way. Stressgen Biotechnologies, another company with an HPV vaccine candidate, is working with Dr. Palefsky, a renowned HPV specialist at UC San Francisco, to study the impact of HPV vaccines for treating HPV-related disease (notably a pre-cancerous condition called AIN). Early findings show that the vaccine (SGN–00101) is safe. There are indications that it may have some benefit in HIV-positive men with AIN. These findings need to be confirmed in larger studies.

Although these vaccines might have limited or no direct impact on most people living with HIV today, they are a welcome advance to everyone concerned about sexual health and, indeed, public health. Some have raised concern that such vaccines would encourage young people to engage in unprotected sex. This argument is simply a rehashing of the old, discredited arguments we have heard against condoms and other efforts to prevent sexually transmitted infections.

Others have raised the concern that vaccination might discourage people from getting screened for HPV-associated cancers. It’s important that young women and their parents learn about age-appropriate GYN screening and symptoms that indicate a need for GYN examination—regardless of available vaccines. It is important to educate all who get the vaccines that they will need to be screened for HPV and associated issues. This is the job of medical providers and sexual health advocates. We applaud the FDA for its decision to make this important vaccine available to young women. We encourage both Merck and GSK to study their vaccines in broader populations, including young men.