Building 29A, NIH Division of Biologics Standards Laboratory Annex, is nationally significant for its association with the history of medicine and public health because within the laboratories of Building 29A, the NIH and then FDA staff helped to conquer some of the deadliest infectious diseases. In their regulatory role they had the national responsibility to license vaccines, antitoxins, blood products, and other biologics to ensure their safety and effectiveness. To support this role, they did scientific research which resulted in the development of important standards and even new vaccines.