New rules for vaccine production

Even though it may be years before this new process is broadly adopted, manufacturers have been granted millions of dollars in research funds to develop the technology as quickly as possible. This may help to boost the production of avian influenza vaccines in the case of a pandemic, as current methods may mean factories cannot make vaccines fast enough to keep up with demand.

"Once you run out of eggs, you can't make more vaccine. But if you have cells banked, you can always make more vaccine," explained Philip Krause, the Food and Drug Administration's deputy director of viral vaccines.

Banks of cells taken either from animals or people already are used to make numerous medical products, including a host of vaccines that protect against such diseases as polio and chickenpox.

Today's egg-based flu vaccine has proven to be effective, but it requires growing flu virus inside tens of millions of eggs from specially raised hens months before the fall vaccination season begins.

The main advantage of the cell-based system is that it would enable faster production if a new flu strain suddenly appeared, because makers wouldn't be limited by availability of the special eggs.