U.S. vaccine supply could be limited in flu pandemic

Most influenza vaccines for Americans are manufactured in other countries-a scenario that could limit U.S. supplies should a swine flu vaccine be needed in the coming months.U.S. government officials have taken steps in recent years to promote more production on U.S. soil by a diverse group of companies, but those efforts are far from complete.If the current strain of swine flu turned into a pandemic, some health experts worry countries might try to reserve flu vaccine for their own citizens...