by Alicia M Prater PhD

Created on: January 18, 2009

On June 8, 2006 the FDA approved Gardasil, made by Merck and Co., as a vaccine for women aged 9-26 years to protect against cervical abnormalities caused by infection with HPV strains 6, 11, 16, and 18. The FDA clinical study summary states that Gardasil does not prevent HPV infection; it protects against the development of cervical cancer which has been shown to be

caused by persistent HPV infection, which actually only occurs in approximately 5% of women.

Gardasil Safety

Long term safety and efficacy studies have not been done on Gardasil. The FDA approved the vaccine based on short term benefits (24 months after the first injection) in women aged 16-26 and a study showing an immune effect in girls aged 9-15. Though the 90-100% efficacy seen in the short term studies is impressive, there have been no studies about the safety of using the vaccine in young girls and no studies of the effect on pregnancies that may occur within 30 days of receiving the vaccine, though it is advised that women thought to be pregnant should not receive the vaccine. However, in the FDA approval it was noted that Merck has promised the FDA that those studies will be done "post-marketing".

The Cervical Cancer Vaccine

The vaccine contains purified viral proteins, called L1. They are non-infectious, but have been shown to activate the immune system in an identical manner to HPV infection. The proteins are injected with an adjuvant, a substance that helps speed the actions of the protein within the vaccine. In the case of Gardasil the adjuvant is an aluminum salt, despite a 2001 research study which found that the HPV-16 L1 protein is sufficient for an immune response and does not need an adjuvant.

In clinical trials more than three quarters of subjects receiving injections of just the aluminum adjuvant had adverse skin reactions; 83% of subjects receiving Gardasil had reactions at the injection site. Only about half of participants who received injections of plain saline had reactions at the injection site. This implicates a problem with the adjuvant solution. Though reactions at the injection site are normal for intramuscular vaccinations, the high rate and the development of reactions up to 5 days after the injections raises questions about the safety of the vaccine.

Gardasil Side Effects

It is no surprise then that there have been reports of fainting and dizziness in young girls who receive the vaccine. The clinical trials saw over half of participants receiving the vaccine experience

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