Growing immunity: These images show insect cells growing without
virus genes (top) and with virus genes (bottom). Scientists say the
approach can produce 100,000 doses of vaccine per week, and can be
adapted for different viruses, including H1N1 (swine flu).
Credit: Protein Sciences
Today's egg-based vaccine technology is slow and unwieldy, requiring at least six months' of production time and millions of eggs to supply enough doses for a regular flu season. If a new virus appears unexpectedly, the antiquated system wouldn't be able to gear up fast enough to produce a new vaccine, many experts agree. What's more, if the virus itself were derived from birds, it might reduce the supply of eggs, hampering the country's main means of vaccine production.