Editing Cancer vaccine (section)

== Prevention vs. treatment ==
Viral vaccines typically work by preventing the spread of the virus. Similarly, cancer vaccines can be designed to target common antigens before cancer evolves if an individual has appropriate risk factors. Additional preventive applications include preventing the cancer from evolving further or undergoing [[metastasis]] and preventing relapse after remission. Therapeutic vaccines focus on killing existing tumors. While cancer vaccines have generally been demonstrated to be safe, their efficacy still needs improvement. One way to potentially improve vaccine therapy is by combining the vaccine with other types of immunotherapy aimed at stimulating the immune system. Since tumors often evolve mechanisms to suppress the immune system, [[immune checkpoint blockade]] has recently received a lot of attention as a potential treatment to be combined with vaccines. For therapeutic vaccines, combined therapies can be more aggressive, but greater care to ensure the safety of relatively healthy patients is needed for combinations involving preventive vaccines.<ref name="Prevent" />