Vaccines and vaccination efforts have effectively prevented many life-threatening or debilitating infectious diseases and are regarded as one of the greatest achievements in the field of public health. There is no doubt that vaccines will continue to be essential for the prevention of infectious diseases with high fatality rates and few treatment options. Meanwhile, as the R&D in vaccines evolves, it has become apparent that vaccines may be used not only to prevent infectious diseases but also to prevent and, more interestingly, treat non-infectious diseases such as cancer.