Td References Td vaccine Ask Anything Homework Help Written by The Information Architects of Encyclopaedia Britannica The Information Architects maintain a master list of the topics included in the corpus of Encyclopædia Britannica, and create and manage the relationships between them. The Information Architects of Encyclopaedia Britannica Britannica AI Ask Anything Learn about this topic in these articles: infectious disease/ Diphtheria toxoid…tetanus toxoid for adults (Td). The Td preparation contains only 15 to 20 percent of the diphtheria toxoid present in the DPT vaccine and is more suitable for use in older children and adults. Read More…tetanus toxoid for adults (Td). The Td preparation contains only 15 to 20 percent of the diphtheria toxoid present in the DPT vaccine and is more suitable for use in older children and adults. Read More