What is the difference between the Gardasil^® and Cervarix^® HPV vaccines?

Gardasil^® is a quadrivalent vaccine with activity against HPV 16 and HPV 18, which are responsible for approximately 70% of all cervical carcinomas. It is also protective against infection with HPV types 6 and 11, which are nononcogenic HPV strains that produce genital warts in both men and women. In contrast, Cervarix^® is a bivalent vaccine with proven protection against the oncogenic strains HPV 16 and 18. There is also some evidence that it produces some protection against other oncogenic HPV types, including HPV 31, 33, and 45.