but for those who don't clear the virus hpv can lead to certain cancers in both women and men. gardasil 9 is the only vaccine that helps protect adults through age 45 against certain diseases caused by hpv, including cervical, vaginal, vulvar, anal, and certain head and neck cancers, such as throat and back of mouth cancers, and genital warts. gardasil 9 doesn't protect everyone and does not treat cancer or hpv infection. your doctor may recommend screening for certain hpv-related cancers. women still need routine cervical cancer screenings. you shouldn't get gardasil 9 if you've had an allergic reaction to the vaccine, its ingredients, or are allergic to yeast. tell your doctor if you have a weakened immune system, are pregnant, or plan to be. the most common side effects include injection site reactions, headache, fever, nausea, dizziness, tiredness, diarrhea, abdominal pain, and sore throat. fainting can also happen after getting gardasil 9. for women and men through age 45 who have not been vaccinated talk to your doctor or pharmacist about your risk for certain hpv-related cancers, and gardasil 9.