Gardasil is a vaccine against certain types of the human papillomavirus (HPV), manufactured by Merck & Co.

Gardasil is designed to prevent infection with HPV types 16, 18, 6, and 11. HPV types 16 and 18 cause about 70% of HPV-related cervical cancer cases. In addition, some types of HPV, particularly type 16, have been found to be associated with oropharyngeal squamous-cell carcinoma, a form of throat cancer. HPV types 6 and 11 cause about 90% of genital wart cases. Human papillomavirus (HPV) infection causes nearly all cases of cervical cancer. Cervical cancer is the second leading cause of death from cancer world-wide , and the leading cause of cancer-related deaths in developing countries. accessed March 7, 2008.

The research that led to the development of the vaccine began in the 1980s by groups at the University of Rochester, Georgetown University, the University of Queensland, and the US National Cancer Institute. In 1991 investigators at the University of Queensland found a way to form non-infectious virus-like particles (VLP), which could also strongly activate the immune system. However, these VLPs assembled poorly and did not have the same structure as infectious HPV. In 1993, a laboratory at the US National Cancer Institute was able to generate HPV16 VLPs that were morphologically correct. These VLPs were the basis for the HPV16 component of the Gardasil vaccine. The history of the discovery of this vaccine is described by McNeil . Upon commercialization of the vaccine, controversy involving intellectual property arose between the various groups that played a role in developing the vaccine.