It is the primary cause of cervical cancer and is also linked to vaginal cancer, penile cancer, anal cancer and genital warts, among other diseases. But the Cleveland Clinic said HPV vaccination protects against 90% of cervical, anal and most throat cancers. The new research found that as vaccination rates increased from 0% to 82% over the 17-year study period, infection rates from different strains of HPV fell by between 75% and 98%. The study found infection rates from two different strains of HPV also had significant reductions — between 72% and 76% — among unvaccinated women, showing evidence of herd immunity. Increasing vaccination rates, including among boys, may partly account for the evidence of herd immunity, the researchers said.