Influenza vaccine development is reviewed as an example of ongoing translational research, which is moving fundamental advances in biology into useful products. The types of new influenza vaccines span the gamut of modern biology research and include new methods of vaccine production (tissue culture compared with egg-produced vaccine). New vaccines being studied include recombinant proteins, polynucleotide vaccines, conjugate vaccines, peptides, expression vectors, and live attenuated vaccines; new adjuvants are being explored to reduce the quantity of antigen needed. The benefits of using reverse genetics are explored. The limits of translational research for predicting clinical results after wide use of vaccines are discussed, including one example of "overinterpretation" of data; some questions should be left to phase IV experience to answer. The pipeline for new influenza vaccines is robust, and recent investment by government and industry in newer vaccines will bring several new products to clinical use.