Can researchers build a better flu vaccine? They probably already have. The FDA has approved two alternatives to traditional egg-based vaccines. One of these, Flucelvax, uses influenza virus grown in kidney cells that were originally obtained from a single cocker spaniel in 1958. The other one, FluBlok, is made by tricking insect cells into pumping out large amounts of hemagglutinin, which is then purified and used in the vaccine. These methods might sound outlandish, but they seem to be safe and effective.