text: Flu Shot Shortage Highlights U.S. Crisis  WASHINGTON (Reuters) - Concerned health officials began  investigating on Friday what went wrong at a British vaccine  plant where half the U.S. flu shots were made, and called on  more companies to get into the vaccine business.
inputs: Flu Shot Shortage Highlights U.S. Crisis  WASHINGTON (Reuters) - Concerned health officials began  investigating on Friday what went wrong at a British vaccine  plant where half the U.S. flu shots were made, and called on  more companies to get into the vaccine business.