CDC and FDA Stand by Merck’s Gardasil

By Dana Zelig, CIS Compliance Specialist
danazelig@cis-partners.com

“The American Cancer Society estimates that in 2008, 11,070 women will be diagnosed with cervical cancer in the U.S.” ~ The Centers for Disease Control and Prevention

The Centers for Disease Control and Prevention (CDC) classify the Human Papillomavirus (HPV) Infection as the most common sexually transmitted disease (STD) in the country. According to the CDC, “Approximately 20 million Americans are currently infected with HPV, and another 6.2 million people become newly infected each year. At least 50% of sexually active men and women acquire genital HPV infection at some point in their lives.”₁ Many of those infected with the virus show no signs or symptoms, and can clear the infection on their own within two years. However, some strains of HPV lead to serious problems like genital warts and cervical cancer, which can be life-threatening and difficult to treat. In response to the increasing prevalence of the virus, Merck developed the Gardasil vaccine, which protects against HPV types 6, 11, 16, and 18 – the types responsible for 70% of cervical cancer cases and 90% of genital wart cases.

On June 8, 2006 the U.S. Food and Drug Administration (FDA) approved Gardasil for use in girls and women ages 9 to 26. Since then, Merck has distributed over 16 million doses in the United States (over 26 million doses worldwide), and the vaccine has been approved for use in 103 countries. As with any widely-distributed vaccine, there are bound to be incidents of adverse events, but in response to recent concerns raised by parents and healthcare groups, Merck and the FDA/CDC are taking these reports very seriously. In a press release posted on July 8, 2008, Merck stated that it “continues to evaluate all safety data in the context of its own post-marketing adverse experience database,” and “participates in the [FDA] and [CDC] adverse event reporting system that collects data on any adverse event following vaccination, whether coincidental or potentially caused by a vaccine.”₂ This system, called the Vaccine Adverse Event Reporting System (VAERS), tracks all adverse events experienced after a vaccination is administered, to identify possible side effects and harmful trends.

As of June 30, 2008, VAERS has received 9,749 reports of adverse events following Gardasil vaccinations; 94% of these events were classified as non-serious, and 6% were classified as serious. Non-serious events included fainting, headache, nausea, fever, and pain at the injection site. All are typical reactions to vaccinations and injections, and are noted in the prescribing information provided by Merck. Reports classified as serious (6% or about 585 out of 9,749 cases) include instances of Guillain-Barre Syndrome (GBS), thromboembolic disorders (blood clots), and in 20 instances, death. Based on their review of the VAERS reports and medical records of affected patients, the FDA and CDC have not been able to prove a causal relationship between the Gardasil vaccine and these serious adverse events. In addition, they have found no evidence that Gardasil increases the rates of these occurrences above those naturally expected in the population.

As a result of these findings, the following statement was posted to the FDA’s Center for Biologics Evaluation and Research (CBER) website:
“CDC has not changed its recommendations for use of Gardasil. FDA has not made any changes to the prescribing information for how the vaccine is used or to the vaccine's Precautions. In addition, FDA routinely reviews manufacturing information, and has not identified any issues affecting the safety, purity and potency of Gardasil.”₃

Still, while the FDA and CDC are satisfied with the safety and efficacy of the vaccine, another battle rages on the state level between lawmakers who support mandating the vaccine for all middle school age girls, and those who feel that 12 year old girls are too young to receive an STD vaccine. On one hand, a mandate would increase Medicare and Medicaid coverage of Gardasil, making it accessible to families who could otherwise not afford it. On the other hand are parents, conservative groups, and vaccine safety advocates who argue that mandating a vaccine for all 12 and 13 year old girls, especially one that has not been proven to last more than 5 years, would do more harm than good. But that’s another article for another day, so stay tuned!

NOTE: On September 12, 2008 the FDA approved expanded uses for Gardasil, which include treatment for certain types of vaginal and vulvar cancers. Update to follow...

For the official FDA news release, see: http://www.fda.gov/bbs/topics/NEWS/2008/NEW01885.html

Sources:

1. “Human Papillomavirus (HPV) Infection”
http://www.cdc.gov/STD/HPV/

2. “Merck Responds to Questions About Adverse Events Reported following Vaccination with GARDASIL”
http://www.merck.com/newsroom/press_releases/product/2008_0708.html

3. “Information from the CDC and FDA on the Safety of Gardasil Vaccine”
http://www.fda.gov/Cber/safety/gardasil071408.htm