Human penis
Vaccinating young people (both girls and boys) before the age when they first have sex can reduce their risk of getting one infection called HPV. The United States CDC says the HPV vaccine should be given at age 11 or 12 years but can be started at age 9. HPV increases the risk of cancer, including cancer in the throat or neck if people have oral sex (licking, kissing or sucking on the penis.) HPV can be under the foreskin if the penis has a foreskin, and in the semen whether the penis is circumcised or uncircumcised.