Several preventive HPV vaccines are available worldwide: A bivalent vaccine that protects against subtypes 16 and 18 (which cause most cervical cancers) A quadrivalent vaccine that protects against subtypes 16 and 18 plus 6 and 11 A 9-valent vaccine that protects against the same subtypes as the quadrivalent plus subtypes 31, 33, 45, 52, and 58 (which cause about 15% of cervical cancers) Subtypes 6 and 11 cause > 90% of visible genital warts.