Both Gardasil and Cervarix are very effective in preventing cervical dysplasia and cervical cancer caused by HPV types 16 and 18. In studies involving thousands of women, the vaccines were over 95 percent effective in preventing cancer and serious dysplasia and over 80 percent effective in preventing milder dysplasia. Preventing mild dysplasia is useful because it reduces the need for additional testing and monitoring of lesions that often go away on their own.
Please remember that these vaccines do not protect against all types of HPV and therefore do not protect against all cases of cervical cancer. Thus they are not a substitute for regular pap smears.
