The 9-valent HPV vaccine (9vHPV) was found to prevent infection and disease caused by HPV types 31, 33, 45, 52, and 58 beyond those already covered by the quadrivalent HPV vaccine (HPV types 6, 11, 16, and 18). A randomized, double-blind study of 14,215 women aged 16-26 found that 9vHPV generated antibody responses to HPV types 6, 11, 16, and 18 that were not inferior to the quadrivalent vaccine. Additionally, rates of HPV related disease for those types were similar between the two groups. Adverse events were generally comparable, though injection site reactions were more common for 9vHPV. The 9vHPV