A new study suggests that the flu shot is so powerful that a half dose may be just as effective as the whole thing. Researchers at Walter Reed Army Medical Center studied over 1,000 healthy adults who had gotten a flu shot within the past one to three years.
Half of them got a full dose of the vaccine and the rest were given a half dose. They found the immune response was nearly the same between the two groups. So why study something like that? Experts say it's good to know if we ever have a flu vaccine shortage again where a limited supply could go twice as far.