Cancer vaccines are a form of immunotherapy aimed at harnessing the body's immune system to fight against cancer cells by reprogramming the immune system and activating T cell mediated adaptive immune response to attack 'foreign' cancer cells. Cancer vaccines are capable of targeting either tumor surface antigens (TSAs) or tumor-associated antigens (TAAs) -TSAs are proteins unique to cancer cells that are not expressed in healthy cells, TAAs on the other hand are expressed in normal as well as cancer cells to differing extents -higher expression levels in cancer cells make them suitable targets for developing cancer vaccines. Cancer vaccines can either be administered as 'preventive' aids or as 'therapeutics' to prevent the occurrence of tumors or cure the disease, respectively. Examples of the former include: Cervarix (GlaxoSmithKline Biologicals), Gardasil-4 (Merck & Co.), Gardasil-9 (Merck Sharp & Dohme LLC), and Hepatitis B (HBV) vaccine (HEPLISAV-B, Dynavax Technologies Corporation) ; examples of the latter include: Bacillus Calmette-Guerin (BCG) and Provenge (sipuleucel-T; Dendreon Pharmaceuticals, LLC). Table 1 highlights a few selected cancer vaccines with respect to their targets, disease indications, companies, and regulatory approval dates.