[Alter Kaker]

Gardasil isn't 100% effective at preventing cervical cancer, since about 30% of cervical cancer isn't related to the HPV virus.

Not quite true. Well over 90% of cervical cancer cases are caused by one of a number of HPV strains. Gardasil protects against the two strains most commonly associated with cervical cancer (along with two other strains associated with genital warts), and it's those two common strains that account for about 70% of cervical cancer cases. That means 20%+ of remaining cases are caused by a variety of rarer HPV strains that Gardasil doesn't target.

[retMD]

Thanks. I took the 70% figure from a fact sheet aimed at the general public. Shame on me - I didn't dig for the details!