The vaccine uses specially engineered bacteria to produce genes of the avian flu H5N1 instead of the conventional, egg-based techniques, adding momentum to developing a faster, safer ways to protect against avian influenza, The Wall Street Journal reported Thursday.

Vical Inc. (NASDAQ:VICL) of San Diego said its Phase 1 clinical trial tested several doses against a placebo in 100 healthy adults and safely triggered an immune response against H5N1.

Rather than using the half-century-old method of growing flu virus in hen's eggs and harvesting it to make a vaccine, Vical produces its vaccine using E. coli bacteria to make the flu-virus genes H5 and M2, the Journal said. Instead of taking months as is the case with the traditional method, Vical's production time is between six to eight weeks, said Vijay B. Samant, Vical's president and chief executive.

Since 2003, the H5N1 virus has caused 243 fatalities among 385 humans who have contracted bird flu. Public health agencies around the world have expressed concern about the virus mutating to a form human-to-human transmission could erupt into a pandemic.