The HPV vaccine is very safe and effective, with no serious side effects. The most common side effect is soreness in the arm. Studies show that the vaccine can protect men against genital warts and cancers. It is likely that this vaccine also protects men from other HPV-related cancers, like cancers of the penis and oropharynx (back of throat, including base of tongue and tonsils), but there are no vaccine studies that have evaluated these outcomes.