US researchers say they have come one step closer to developing a tougher, more flexible bird flu vaccine that could be produced significantly faster than traditional vaccines and would also protect against future virus mutations. The vaccine would be delivered by a harmless virus that could be developed in tissue cultures rather than chicken eggs.This would guard against concern that eggs could become scarce during a pandemic and also allows for significantly faster and larger production cycles, said lead researcher Suresh Mittal at Purdue University in Indiana.
