There is a lot of potential in creating a flu vaccine that would make us immune to all currently known strains and all potential future strains of the flu. This vaccine would work either by blocking the receptor sites that strains of the flu generally attack or making a generalized flu strain that allows the human body to mutate the strain into any possible strain of the flu, and thus develop a resistance to any of those strains. It could involve some type of bio-engineered disease, or some type of bio-engineered technology.