The DPT vaccine or DTP vaccine is a class of combination vaccines to protect
against three infectious diseases in humans: diphtheria, pertussis (whooping cough), and tetanus (lockjaw).[7] The vaccine components include diphtheria and tetanus toxoids, and either killed whole cells of the bacterium that causes pertussis or pertussis antigens. The term toxoid refers to vaccines which use an inactivated toxin produced by the pathogen which they are targeted against to generate an immune response. In this way, the toxoid vaccine generates an immune response which is targeted against the toxin which is produced by the pathogen and causes disease, rather than a vaccine which is targeted against the pathogen itself.[8] The whole cells or antigens will be depicted as either "DTwP"[9] or "DTaP", where the lower-case "w" indicates whole-cell inactivated pertussis and the lower-case "a" stands for "acellular".[10] In comparison to alternative vaccine types, such as live attenuated vaccines, the DTP vaccine does not contain any live pathogen, but rather uses inactivated toxoid (and for pertussis, either a dead pathogen or pure antigens) to generate an immune response; therefore, there is not a risk of use in populations that are immune compromised since there is not any known risk of causing the disease itself. As a result, the DTP vaccine is considered a safe vaccine to use in anyone and it generates a much more targeted immune response specific for the pathogen of interest.[11]
In the United States, the DPT (whole-cell) vaccine was administered as part of the childhood vaccines recommended by the Centers for Disease Control and Prevention (CDC) until 1996, when the acellular DTaP vaccine was licensed for use.[12]
Unless otherwise noted, this article uses "DPT" and "DTP" to refer to any combination vaccine that targets diphtheria, tetanus, and pertussis. The whole-cell vaccine is mentioned either as DTwP or as its historical name (DPT/DTP) with parenthetical remarks.