Shortage: Vaccine Worries

United States-At this time last year, the United States} supply of tetanus vaccine was easily met by the two companies licensed to produce it there, Aventis Pasteur and Wyeth-Ayerst. But in June 2000, the latter ran into regulatory problems, and FDA seized thousands of substandard doses of acellular pertussis vaccine from the company}s Marietta, Pennsylvania, plant.