Scientists say they are one step closer to establishing a way to double the U.S. supply of flu vaccine, which could ward off the possibility of shortages.According to a new study based on a method already in use in Europe, only half the current amount of antigen — the vaccine component that generates our immune response – would be needed to produce the vaccines for avian and swine flu, and those vaccines’ effectiveness would increase. The antigen is often the limiting factor in vaccine production.
