Most people think vaccine history is just Jenner, a gap, then polio, and then we figured it out. The real story is far more interesting. This episode traces five distinct platform shifts in vaccine technology — from whole-pathogen vaccines to recombinant proteins, conjugate vaccines, and the new genetic era of mRNA and viral vectors. We explore the bottlenecks that stalled progress for nearly a century, the accidental discoveries that broke them open, and what's actually in the pipeline today: universal flu vaccines targeting the stalk instead of the head, personalized cancer vaccines made from a patient's own tumor mutations, and needle-free delivery systems. The technology is not in maintenance mode — it's accelerating.