During the last quarter of 2000, the U.S. Public Health Service learned of a shortage of tetanus and diphtheria toxoids (Td) and tetanus toxoid (TT) resulting from decreased production of these vaccines by the two U.S. manufacturers. Previously published recommendations outlined priorities for use of the limited supply of Td and TT. The shortage was expected to be resolved by early 2001; however, on January 10, 2001, Wyeth Lederle (Pearl River, New York) announced it had stopped production of tetanus toxoid-containing products. Although a small amount of Td is produced by the University of Massachusetts for local distribution, Aventis Pasteur (Swiftwater, Pennsylvania) is now the sole nationwide distributor of Td and TT. Aventis Pasteur is shipping limited quantities of vaccine to assure a wide distribution of available doses.