The unprecedented production snag has occurred because one of the flu strains in this year's vaccine has grown more slowly than expected in laboratories and two of the four companies licensed to make the vaccine in the United States have experienced manufacturing problems. The CDC said, based on current estimates, that the amount of flu vaccine available this year could be substantially less than in 1999, though the extent of the problem will likely become more clear within the next two months. Dr. Keiji Fukuda, chief of epidemiology in the CDC's flu branch, told a federal advisory committee on immunization in Atlanta. If a shortage develops, the federal government may recommend that people who are not at high risk of influenza opt to delay their shots until January, the height of the flu season.
Most people get their flu shots in the last three months of the year.
The CDC recommends influenza vaccinations for all people aged 50 years and older and those suffering from diabetes, immunosuppression disorders, severe forms of anemia and chronic diseases of the heart, lungs or kidneys. An estimated 114,000 Americans require hospital treatment and 20,000 die every year from influenza. Dr. Roland Levandowski, a supervising medical officer at the FDA's Center for Biologics, noted that the agency had identified vaccine manufacturing problems at The Parkedale Pharmaceuticals Inc. in Rochester, Michigan, and Wyeth Laboratories Inc. in Marietta, Pennsylvania. The FDA said Parkedale was notified on March 20 to cease production and distribution of flu vaccine until the problems were corrected.