Impact of Human Papillomavirus (HPV) Vaccination on Burden of Disease in Patients with Actinic Keratosis

Inclusion Criteria: Subjects who meet all the following criteria are eligible to participate in this study: 1. High AK burden, defined as ≥15 AK lesions in the included test area (50-100 cm2) at baseline 2. Test area does not involve the ala nasi, eyelids, nasolabial folds, or periauricular skin 3. \>18 years of age at baseline 4. Fitzpatrick skin phototype I-IV 5. Legally competent, able to give verbal and written informed consent 6. Subject is willing to participate and can comply with protocol requirements including the refraining from other therapy (with the exception of KC treatment) in the test area for the duration of the trial. 7. Women of childbearing potential1 must be confirmed not pregnant by a negative urine pregnancy test prior to trial treatment and be on effective contraception2 until discontinuation of the vaccine therapy. Additional pregnancy testing will not be conducted unless pregnancy is suspected. 1Female subjects are considered of childbearing potential unless they have been hysterectomized or have undergone tubal ligation or have been post-menopausal for at least one year prior to first visit. 2Intrauterine device or hormonal contraception (oral, implant, patch, vaginal ring, injection). Exclusion Criteria: Subjects meeting any of the following criteria are not eligible to participate in this study: 1. Known or suspected immunosuppression (by disease or immunosuppressive drug) 2. History of vaccine-related allergic reactions or known allergy to Gardasil®9 ingredients or yeast 3. Previously vaccinated with any HPV vaccine 4. History of keloids 5. Other skin diseases present in the test area at baseline 6. Lactating or pregnant women