Gardasil is a vaccination given to adolescent girls to prevent human papilloma virus (HPV), which causes 99% of cervical cancer in women. Gardasil was approved for use by the FDA in 2006, and by the beginning of 2009, over 23 million Gardasil vaccinations had been administered in the United States. Recently, the vaccine has been linked to Guillain-Barre Syndrome (GBS), which is a rare but serious nervous disorder.